text:
HDAC inhibition modulates hippocampus-dependent long-term memory for object location in a CBP-dependent manner
Digital Repository Infrastructure Vision for European Research (DRIVER)
Transcription of genes required for long-term memory not only involves transcription factors, but also enzymatic protein complexes that modify chromatin structure. Chromatin-modifying enzymes, such as the histone acetyltransferase (HAT) CREB (cyclic-AMP response element binding) binding protein (CBP), are pivotal for the transcriptional regulation required for long-term memory. Several studies have shown that CBP and histone acetylation are necessary for hippocampus-dependent long-term memory...
Haettig, Jakob; Stefanko, Daniel P.; Multani, Monica L.; Figueroa, Dario X.; Mcquown, Susan C.; Wood, Marcelo A.
Nicotine shifts the temporal activation of hippocampal protein kinase A and extracellular signal-regulated kinase 1/2 to enhance long-term, but not short-term, hippocampus-dependent memory.
Acute nicotine enhances hippocampus-dependent learning through nicotine binding to ?2-containing nicotinic acetylcholine receptors (nAChRs), but it is unclear if nicotine is targeting processes involved in short-term memory (STM) leading to a strong long-term memory (LTM) or directly targeting LTM. In addition, the molecular mechanisms involved in the effects of nicotine on learning are unknown. Previous research indicates that protein kinase A (PKA), extracellular signal-regulated kinase 1/2 (ERK1/2), and protein synthesis are crucial for LTM. Therefore, the present study examined the effects of nicotine on STM and LTM and the involvement of PKA, ERK1/2, and protein synthesis in the nicotine-induced enhancement of hippocampus-dependent contextual learning in C57BL/6J mice. The protein synthesis inhibitor anisomycin impaired contextual conditioning assessed at 4 h but not 2 h post-training, delineating time points for STM (2 h) and LTM (4 h and beyond). Nicotine enhanced contextual conditioning at 4, 8, and 24 h but not 2 h post-training, indicating nicotine specifically enhances LTM but not STM. Furthermore, nicotine did not rescue deficits in contextual conditioning produced by anisomycin, suggesting that the nicotine enhancement of contextual conditioning occurs through a protein synthesis-dependent mechanism. In addition, inhibition of dorsal hippocampal PKA activity blocked the effect of acute nicotine on learning, and nicotine shifted the timing of learning-related PKA and ERK1/2 activity in the dorsal and ventral hippocampus. Thus, the present results suggest that nicotine specifically enhances LTM through altering the timing of PKA and ERK1/2 signaling in the hippocampus, and suggests that the timing of PKA and ERK1/2 activity could contribute to the strength of memories. PMID:24457151
Gould, Thomas J; Wilkinson, Derek S; Yildirim, Emre; Poole, Rachel L F; Leach, Prescott T; Simmons, Steven J
Resistance exercise improves hippocampus-dependent memory
Digital Repository Infrastructure Vision for European Research (DRIVER)
It has been demonstrated that resistance exercise improves cognitive functions in humans. Thus, an animal model that mimics this phenomenon can be an important tool for studying the underlying neurophysiological mechanisms. Here, we tested if an animal model for resistance exercise was able to improve the performance in a hippocampus-dependent memory task. In addition, we also evaluated the level of insulin-like growth factor 1/insulin growth factor receptor (IGF-1/IGF-1R), which plays pleiot...
Cassilhas, R. C.; Lee, K. S.; Vena?ncio, D. P.; Oliveira, M. G. M.; Tufik, S.; Mello, M. T.
Resistance exercise improves hippocampus-dependent memory
Directory of Open Access Journals (Sweden)
Full Text Available It has been demonstrated that resistance exercise improves cognitive functions in humans. Thus, an animal model that mimics this phenomenon can be an important tool for studying the underlying neurophysiological mechanisms. Here, we tested if an animal model for resistance exercise was able to improve the performance in a hippocampus-dependent memory task. In addition, we also evaluated the level of insulin-like growth factor 1/insulin growth factor receptor (IGF-1/IGF-1R, which plays pleiotropic roles in the nervous system. Adult male Wistar rats were divided into three groups (N = 10 for each group: control, SHAM, and resistance exercise (RES. The RES group was submitted to 8 weeks of progressive resistance exercise in a vertical ladder apparatus, while the SHAM group was left in the same apparatus without exercising. Analysis of a cross-sectional area of the flexor digitorum longus muscle indicated that this training period was sufficient to cause muscle fiber hypertrophy. In a step-through passive avoidance task (PA, the RES group presented a longer latency than the other groups on the test day. We also observed an increase of 43 and 94% for systemic and hippocampal IGF-1 concentration, respectively, in the RES group compared to the others. A positive correlation was established between PA performance and systemic IGF-1 (r = 0.46, P < 0.05. Taken together, our data indicate that resistance exercise improves the hippocampus-dependent memory task with a concomitant increase of IGF-1 level in the rat model. This model can be further explored to better understand the effects of resistance exercise on brain functions.
R.C. Cassilhas
Epac signaling is required for hippocampus-dependent memory retrieval
Digital Repository Infrastructure Vision for European Research (DRIVER)
Previously we uncovered a critical role for norepinephrine and ?1-adrenergic signaling in hippocampus-dependent memory retrieval. Because the ?1 receptor couples to Gs, we examine here whether cAMP is also required for contextual memory retrieval. Using pharmacologic and genetic approaches to manipulate cAMP and downstream signaling, we demonstrate that cAMP and two of its targets, protein kinase A (PKA) and exchange protein activated by cAMP (Epac), are both required for retrieval. These f...
Ouyang, Ming; Zhang, Lei; Zhu, J. Julius; Schwede, Frank; Thomas, Steven A.
Circadian Oscillations within the Hippocampus Support Hippocampus-dependent Memory Processing
Directory of Open Access Journals (Sweden)
Full Text Available The ability to sustain memories over long periods of time, sometimes even a lifetime, is one of the most remarkable properties of the brain. Much knowledge has been gained over the past few decades regarding the molecular correlates of memory formation. Once a memory is forged, however, the molecular events that provide permanence are as of yet unclear. Studies in multiple organisms have revealed that circadian rhythmicity is important for the formation, stability, and recall of memories [1]. The neuronal events that provide this link need to be explored further. This article will discuss the findings related to the circadian regulation of memory-dependent processes in the hippocampus. Specifically, the circadian-controlled MAP kinase and cAMP signal transduction pathway plays critical roles in the consolidation of hippocampus-dependent memory. A series of studies have revealed the circadian oscillation of this pathway within the hippocampus, an activity that is absent in memory-deficient, transgenic mice lacking Ca2+-stimulated adenylyl cyclases. Interference with these oscillations proceeding the cellular memory consolidation period impairs the persistence of hippocampus-dependent memory. These data suggest that the persistence of long-term memories may depend upon reactivation of this signal transduction pathway in the hippocampus during the circadian cycle. New data reveals the dependence of hippocampal oscillation in MAPK activity on the SCN, again underscoring the importance of this region in maintaining the circadian physiology of memory. Finally, the downstream ramification of these oscillations in terms of gene expression and epigenetics should be considered, as emerging evidence is pointing strongly to a circadian link between epigenetics and long term synaptic plasticity.
Inhibition of neurogenesis interferes with hippocampus-dependent memory function.
Rats treated with low dose irradiation, to inhibit adult hippocampal neurogenesis, and control rats were administered a non-matching-to-sample (NMTS) task, which measured conditional rule learning and memory for specific events, and a test of fear conditioning in which a discrete CS was paired with an aversive US in a complex environment. Irradiated rats were impaired on the NMTS task when the intervals between sample and test trials were relatively long, and in associating the shock-induced fear with contextual cues in the fear conditioning task. Irradiated rats were not impaired in learning the basic NMTS rule or in performing that task when the intervals between the sample and test trials were short. Nor were there group differences in conditioning the fear response to the CS in the fear conditioning task. The results, which extend the range of hippocampus-dependent tasks that can be said to be vulnerable to the effects of neurogenesis suppression, support the hypothesis that new hippocampal cells generated in adulthood participate in a broad range of hippocampal functions. PMID:16411241
Winocur, Gordon; Wojtowicz, J Martin; Sekeres, Melanie; Snyder, Jason S; Wang, Sabrina
Xamoterol impairs hippocampus-dependent emotional memory retrieval via Gi/o-coupled ?2-adrenergic signaling
Digital Repository Infrastructure Vision for European Research (DRIVER)
Xamoterol, a partial ?1-adrenergic receptor agonist, has been reported to impair the retrieval of hippocampus-dependent spatial reference memory in rats. In contrast, xamoterol restores memory retrieval in gene-targeted mice lacking norepinephrine (NE) and in a transgenic mouse model of Down syndrome in which NE levels are reduced. Restoration of retrieval by xamoterol in these two models complements the observation that NE and ?1 signaling are required for hippocampus-dependent retrieval o...
Schutsky, Keith; Ouyang, Ming; Thomas, Steven A.
Role of adult neurogenesis in hippocampus-dependent memory, contextual fear extinction and remote contextual memory: new insights from ERK5 MAP kinase.
Adult neurogenesis occurs in two discrete regions of the adult mammalian brain, the subgranular zone (SGZ) of the dentate gyrus (DG) and the subventricular zone (SVZ) along the lateral ventricles. Signaling mechanisms regulating adult neurogenesis in the SGZ are currently an active area of investigation. Adult-born neurons in the DG functionally integrate into the hippocampal circuitry and form functional synapses, suggesting a role for these neurons in hippocampus-dependent memory formation. Although results from earlier behavioral studies addressing this issue were inconsistent, recent advances in conditional gene targeting technology, viral injection and optogenetic approaches have provided convincing evidence supporting a role for adult-born neurons in the more challenging forms of hippocampus-dependent learning and memory. Here, we briefly summarize these recent studies with a focus on extra signal-regulated kinase (ERK) 5, a MAP kinase whose expression in the adult brain is restricted to the neurogenic regions including the SGZ and SVZ. We review evidence identifying ERK5 as a novel endogenous signaling pathway that regulates the pro-neural transcription factor Neurogenin 2, is activated by neurotrophins and is critical for adult neurogenesis. We discuss studies demonstrating that specific deletion of ERK5 in the adult neurogenic regions impairs several forms of hippocampus-dependent memory formation in mice. These include contextual fear memory extinction, the establishment and maintenance of remote contextual fear memory, and several other challenging forms of hippocampus-dependent memory formation including 48h memory for novel object recognition, contextual fear memory established by a weak foot shock, pattern separation, and reversal of spatial learning and memory. We also briefly discuss current evidence that increasing adult neurogenesis, by small molecules or genetic manipulation, improves memory formation and long-term memory. PMID:23871742
Pan, Yung-Wei; Storm, Daniel R; Xia, Zhengui
Long-term potentiation and memory.
Digital Repository Infrastructure Vision for European Research (DRIVER)
The discovery of long-term potentiation (LTP) transformed research on the neurobiology of learning and memory. This did not happen overnight, but the discovery of an experimentally demonstrable phenomenon reflecting activity-driven neuronal and synaptic plasticity changed discussions about what might underlie learning from speculation into something much more concrete. Equally, however, the relationship between the discovery of LTP and research on the neurobiology of learning and memory has b...
Morris, Richard G. M.
Andra long term memory project - 59277
International Nuclear Information System (INIS)
Document available in abstract form only. Full text of publication follows: Long term memory of repositories is required by safety, reversibility and social expectations. Thus Andra has implemented since 2010 a long-term memory project to reinforce and diversify its current arrangements in this field, as well as to explore opportunities to extend memory keeping over thousands years. The project includes opportunity studies of dedicated facilities. The 'Ecotheque' and 'Geotheque' projects contribute to memory respectively through environmental and geological samples preservation. The options of creating (i) an archive centre for Andra's interim and permanent archives, (ii) an artist center to study the contribution of arts to memory preservation, (iii) a museum of radioactive waste disposal history and technology (radium industry..., sea disposal, current solutions...) are considered. Other studies provided by the project examine our heritage. This includes the continuity of languages and symbolic systems, the continuity of writing and engraving methods, the archaeology of landscapes (memory of the earths evolution, multi-century memory of industrial and agricultural landscapes), the archaeology practices (how might a future archaeologist be interested in our current activity?), the preservation of historical sites and industrial memory, the continuity of institutional organizations, the memory and history of science evolution as well as broad history
Regulation of hippocampus-dependent memory by the zinc finger protein Zbtb20 in mature CA1 neurons.
The mammalian hippocampus harbours neural circuitry that is crucial for associative learning and memory. The mechanisms that underlie the development and regulation of this complex circuitry are not fully understood. Our previous study established an essential role for the zinc finger protein Zbtb20 in the specification of CA1 field identity in the developing hippocampus. Here, we show that conditionally deleting Zbtb20 specifically in mature CA1 pyramidal neurons impaired hippocampus-dependent memory formation, without affecting hippocampal architecture or the survival, identity and basal excitatory synaptic activity of CA1 pyramidal neurons. We demonstrate that mature CA1-specific Zbtb20 knockout mice exhibited reductions in long-term potentiation (LTP) and NMDA receptor (NMDAR)-mediated excitatory post-synaptic currents. Furthermore, we show that activity-induced phosphorylation of ERK and CREB is impaired in the hippocampal CA1 of Zbtb20 mutant mice. Collectively, these results indicate that Zbtb20 in mature CA1 plays an important role in LTP and memory by regulating NMDAR activity, and activation of ERK and CREB. PMID:22777671
Ren, Anjing; Zhang, Huan; Xie, Zhifang; Ma, Xianhua; Ji, Wenli; He, David Z Z; Yuan, Wenjun; Ding, Yu-Qiang; Zhang, Xiao-Hui; Zhang, Weiping J
Mice create what-where-when hippocampus-dependent memories of unique experiences.
Episodic memory is relevant for auto-consciousness in humans. In nonhuman animals, episodic-like memory is defined when the "what-where-when" content of a unique event forms an integrated cognitive representation that is then deployed during memory retrieval. Here, we aimed at testing episodic-like memories of mice under experimental conditions that allow the analysis of whether and how mice process what-where-when information. Using an ecologically relevant paradigm for spontaneous learning and memory, we show that mice modulate their behavior based on the what, where, and when components of past unique episodes, specifically on previous encounters of conspecifics at a defined location and at a specific time of the day. We also show that learning during this paradigm activated Arc/Arg3.1 mRNA expression in the hippocampus and that stereotactic injection of anisomycin into this region impairs memory consolidation. Thus, hippocampus-dependent episodic-like memories of single experiences are spontaneously created in mice. These findings extend our knowledge of the cognitive capacities of the mouse and suggest that this species can be used as model for studying the mechanisms underlying human episodic memory and related neurological disorders. PMID:23325241
Fellini, Laetitia; Morellini, Fabio
Onset of hippocampus-dependent memory impairments in 5XFAD transgenic mouse model of Alzheimer's disease.
The 5XFAD mice are an early-onset transgenic model of Alzheimer's disease (AD) in which amyloid plaques are first observed between two and four months of age in the cortical layer five and in the subiculum of the hippocampal formation. Although cognitive alterations have been described in these mice, there are no studies that focused on the onset of hippocampus-dependent memory deficits, which are a hallmark of the prodromal stage of AD. To identify when the first learning and memory impairments appear, 5XFAD mice of two, four, and six months of age were compared with their respective wild-type littermates using the olfactory tubing maze, which is a very sensitive hippocampal-dependent task. Deficits in learning and memory started at four months with a substantial increase at six months of age while no olfactory impairments were observed. The volumetric study using magnetic resonance imaging of the whole brain and specific areas (olfactory bulb, striatum, and hippocampus) did not reveal neuro-anatomical difference. Slight memory deficits appeared at 4 months of age in correlation with an increased astrogliosis and amyloid plaque formation. This early impairment in learning and memory related to the hippocampal dysfunction is particularly suited to assess preclinical therapeutic strategies aiming to delay or suppress the onset of AD. � 2014 Wiley Periodicals, Inc. PMID:24596271
Girard, St�phane D; Jacquet, Marlyse; Baranger, K�vin; Migliorati, Martine; Escoffier, Guy; Bernard, Anne; Khrestchatisky, Michel; F�ron, Fran�ois; Rivera, Santiago; Roman, Fran�ois S; Marchetti, Evelyne
Genetic variation of the RASGRF1 regulatory region affects human hippocampus-dependent memory.
The guanine nucleotide exchange factor RASGRF1 is an important regulator of intracellular signaling and neural plasticity in the brain. RASGRF1-deficient mice exhibit a complex phenotype with learning deficits and ocular abnormalities. Also in humans, a genome-wide association study has identified the single nucleotide polymorphism (SNP) rs8027411 in the putative transcription regulatory region of RASGRF1 as a risk variant of myopia. Here we aimed to assess whether, in line with the RASGRF1 knockout mouse phenotype, rs8027411 might also be associated with human memory function. We performed computer-based neuropsychological learning experiments in two independent cohorts of young, healthy participants. Tests included the Verbal Learning and Memory Test (VLMT) and the logical memory section of the Wechsler Memory Scale (WMS). Two sub-cohorts additionally participated in functional magnetic resonance imaging (fMRI) studies of hippocampus function. 119 participants performed a novelty encoding task that had previously been shown to engage the hippocampus, and 63 subjects participated in a reward-related memory encoding study. RASGRF1 rs8027411 genotype was indeed associated with memory performance in an allele dosage-dependent manner, with carriers of the T allele (i.e., the myopia risk allele) showing better memory performance in the early encoding phase of the VLMT and in the recall phase of the WMS logical memory section. In fMRI, T allele carriers exhibited increased hippocampal activation during presentation of novel images and during encoding of pictures associated with monetary reward. Taken together, our results provide evidence for a role of the RASGRF1 gene locus in hippocampus-dependent memory and, along with the previous association with myopia, point toward pleitropic effects of RASGRF1 genetic variations on complex neural function in humans. PMID:24808846
Barman, Adriana; Assmann, Anne; Richter, Sylvia; Soch, Joram; Sch�tze, Hartmut; W�stenberg, Torsten; Deibele, Anna; Klein, Marieke; Richter, Anni; Behnisch, Gusalija; D�zel, Emrah; Zenker, Martin; Seidenbecher, Constanze I; Schott, Bj�rn H
Genetic variation of the RASGRF1 regulatory region affects human hippocampus-dependent memory
Directory of Open Access Journals (Sweden)
Full Text Available The guanine nucleotide exchange factor RASGRF1 is an important regulator of intracellular signaling and neural plasticity in the brain. RASGRF1-deficient mice exhibit a complex phenotype with learning deficits and ocular abnormalities. Also in humans, a genome-wide association study has identified the single nucleotide polymorphism (SNP rs8027411 in the putative transcription regulatory region of RASGRF1 as a risk variant of myopia. Here we aimed to assess whether, in line with the RASGRF1 knockout mouse phenotype, rs8027411 might also be associated with human memory function. We performed computer-based neuropsychological learning experiments in two independent cohorts of young, healthy participants. Tests included the Verbal Learning and Memory Test (VLMT and the logical memory section of the Wechsler Memory Scale (WMS. Two sub-cohorts additionally participated in functional magnetic resonance imaging (fMRI studies of hippocampus function. 119 participants performed a novelty encoding task that had previously been shown to engage the hippocampus, and 63 subjects participated in a reward-related memory encoding study. RASGRF1 rs8027411 genotype was indeed associated with memory performance in an allele dosage-dependent manner, with carriers of the T allele (i.e. the myopia risk allele showing better memory performance in the early encoding phase of the VLMT and in the recall phase of the WMS logical memory section. In fMRI, T allele carriers exhibited increased hippocampal activation during presentation of novel images and during encoding of pictures associated with monetary reward. Taken together, our results provide evidence for a role of the RASGRF1 gene locus in hippocampus-dependent memory and, along with the previous association with myopia, point towards pleitropic effects of RASGRF1 genetic variations on complex neural function in humans.
Distinctions between orthographic long-term memory and working memory
Digital Repository Infrastructure Vision for European Research (DRIVER)
Research in the cognitive and neural sciences has long posited a distinction between the long-term memory (LTM) storage of information and the short-term buffering of information that is being actively manipulated in working memory (WM). This basic type of distinction has been posited in a variety of domains, including written language production�spelling. In the domain of spelling, the primary source of empirical evidence regarding this distinction has been cognitive neuropsychological stu...
Buchwald, Adam; Rapp, Brenda
"Gadd45b" Knockout Mice Exhibit Selective Deficits in Hippocampus-Dependent Long-Term Memory
Growth arrest and DNA damage-inducible [beta] ("Gadd45b") has been shown to be involved in DNA demethylation and may be important for cognitive processes. "Gadd45b" is abnormally expressed in subjects with autism and psychosis, two disorders associated with cognitive deficits. Furthermore, several high-throughput screens have identified "Gadd45b"�
Leach, Prescott T.; Poplawski, Shane G.; Kenney, Justin W.; Hoffman, Barbara; Liebermann, Dan A.; Abel, Ted; Gould, Thomas J.
Strain-dependent Differences in LTP and Hippocampus-dependent Memory in Inbred Mice
Digital Repository Infrastructure Vision for European Research (DRIVER)
Many studies have used �reverse� genetics to produce �knock-out� and transgenic mice to explore the roles of various molecules in long-term potentiation (LTP) and spatial memory. The existence of a variety of inbred strains of mice provides an additional way of exploring the genetic bases of learning and memory. We examined behavioral memory and LTP expression in area CA1 of hippocampal slices prepared from four different inbred strains of mice: C57BL/6J, CBA/J, DBA/2J, and 129/SvEms-...
Nguyen, Peter V.; Abel, Ted; Kandel, Eric R.; Bourtchouladze, Roussoudan
Developmental Dyslexia and Explicit Long-Term Memory
The reduced verbal long-term memory capacities often reported in dyslexics are generally interpreted as a consequence of their deficit in phonological coding. The present study was aimed at evaluating whether the learning deficit exhibited by dyslexics was restricted only to the verbal component of the long-term memory abilities or also involved�
Menghini, Deny; Carlesimo, Giovanni Augusto; Marotta, Luigi; Finzi, Alessandra; Vicari, Stefano
Item-location binding in working memory: Is it hippocampus-dependent?
A general consensus is emerging that the hippocampus has an important and active role in the creation of new long-term memory representations of associations or bindings between elements. However, it is less clear whether this contribution can be extended to the creation of temporary bound representations in working memory, involving the retention of small numbers of items over short delays. We examined this by administering a series of recognition and recall tests of working memory for colour-location binding and object-location binding to a patient with highly selective hippocampal damage (Jon), and groups of control participants. Jon achieved high levels of accuracy in all working memory tests of recognition and recall binding across retention intervals of up to 10s. In contrast, Jon performed at chance on an unexpected delayed test of the same object-location binding information. These findings indicate a clear dissociation between working memory and long-term memory, with no evidence for a critical hippocampal contribution to item-location binding in working memory. PMID:24784006
Allen, Richard J; Vargha-Khadem, Faraneh; Baddeley, Alan D
Hypocretin/orexin neurons contribute to hippocampus-dependent social memory and synaptic plasticity in mice.
Hypocretin/orexin (Hcrt)-producing neurons in the lateral hypothalamus project throughout the brain, including to the hippocampus, where Hcrt receptors are widely expressed. Hcrt neurons activate these targets to orchestrate global arousal state, wake-sleep architecture, energy homeostasis, stress adaptation, and reward behaviors. Recently, Hcrt has been implicated in cognitive functions and social interaction. In the present study, we tested the hypothesis that Hcrt neurons are critical to social interaction, particularly social memory, using neurobehavioral assessment and electrophysiological approaches. The validated "two-enclosure homecage test" devices and procedure were used to test sociability, preference for social novelty (social novelty), and recognition memory. A conventional direct contact social test was conducted to corroborate the findings. We found that adult orexin/ataxin-3-transgenic (AT) mice, in which Hcrt neurons degenerate by 3 months of age, displayed normal sociability and social novelty with respect to their wild-type littermates. However, AT mice displayed deficits in long-term social memory. Nasal administration of exogenous Hcrt-1 restored social memory to an extent in AT mice. Hippocampal slices taken from AT mice exhibited decreases in degree of paired-pulse facilitation and magnitude of long-term potentiation, despite displaying normal basal synaptic neurotransmission in the CA1 area compared to wild-type hippocampal slices. AT hippocampi had lower levels of phosphorylated cAMP response element-binding protein (pCREB), an activity-dependent transcription factor important for synaptic plasticity and long-term memory storage. Our studies demonstrate that Hcrt neurons play an important role in the consolidation of social recognition memory, at least in part through enhancements of hippocampal synaptic plasticity and cAMP response element-binding protein phosphorylation. PMID:23516292
Yang, Liya; Zou, Bende; Xiong, Xiaoxing; Pascual, Conrado; Xie, James; Malik, Adam; Xie, Julian; Sakurai, Takeshi; Xie, Xinmin Simon
Effects of Acute Exercise on Long-Term Memory
In this study, we tested the effect of acute exercise on long-term memory, specifically the timing of exercise relative to the memory challenge. We assessed memory via paragraph recall, in which participants listened to two paragraphs (exposure) and recounted them following a 35-min delay. Participants (n = 48) were randomly assigned to one of�
Labban, Jeffrey D.; Etnier, Jennifer L.
Practicing memory retrieval improves long-term retention in rats.
The view that the human mind is a repository of stored items dates at least to Aristotle and Plato and continues to dominate investigations of human memory. This view fits with our intuitions that we study information as the optimal method to store information in memory and that retrieval of information functions only to assess what information was previously stored. Yet modern research on human memory suggests that retrieving information during a test facilitates later memory of that information. Because human memory is intertwined with language, it is difficult to resist the conclusion that language is essential for this key aspect of human cognition. Here we show that practising memory retrieval improves long-term retention in a nonhuman species. We report evidence that rats' long-term memory performance is enhanced if they had previously retrieved specific items stored in memory. PMID:24028945
Crystal, Jonathon D; Ketzenberger, J Aaron; Alford, Wesley T
Long Term Potentiation as a Mechanism for Learning and Memory
Digital Repository Infrastructure Vision for European Research (DRIVER)
Since the 1970s when long term potentiation (LTP) was introduced to the scientific world;several studies have been devoted to determining whether this phenomenon is naturally abasic mechanism of learning and memory in mammalian brains. However, plenty of evidenceconfirms that a) LTP is inducible in the circuits involved in learning and memory; b) commonreceptors and intracellular cascades are recruited in both memory and synaptic plasticityand c) LTP and memory are similarly affected by many ...
Enhanced long-term and impaired short-term spatial memory in GluA1 AMPA receptor subunit knockout mice: Evidence for a dual-process memory model
Digital Repository Infrastructure Vision for European Research (DRIVER)
The GluA1 AMPA receptor subunit is a key mediator of hippocampal synaptic plasticity and is especially important for a rapidly-induced, short-lasting form of potentiation. GluA1 gene deletion impairs hippocampus-dependent, spatial working memory, but spares hippocampus-dependent spatial reference memory. These findings may reflect the necessity of GluA1-dependent synaptic plasticity for short-term memory of recently visited places, but not for the ability to form long-term associations betwee...
Sanderson, Dj; Good, Ma; Skelton, K.; Sprengel, R.; Seeburg, Ph; Rawlins, Jn; Bannerman, Dm
The neuronal response at extended timescales: long-term correlations without long-term memory
Directory of Open Access Journals (Sweden)
Full Text Available Long term temporal correlations frequently appear at many levels of neural activity. We show that when such correlations appear in isolated neurons, they indicate the existence of slow underlying processes and lead to explicit conditions on the dynamics of these processes. Moreover, although these slow processes can potentially store information for long times, we demonstrate that this does not imply that the neuron possesses a long memory of its input, even if these processes are bidirectionally coupled with neuronal response. We derive these results for a broad class of biophysical neuron models, and then fit a specific model to recent experiments. The model reproduces the experimental results, exhibiting long term (days-long correlations due to the interaction between slow variables and internal fluctuations. However, its memory of the input decays on a timescale of minutes. We suggest experiments to test these predictions directly.
D-Cycloserine Enhances Memory Consolidation of Hippocampus-Dependent Latent Extinction
Adult male Long-Evans rats were trained to run in a straight-alley maze for food reward and subsequently received hippocampus-dependent latent extinction training. Immediately following latent extinction, rats received peripheral injections of the NMDA receptor partial agonist D-cycloserine (DCS, 15 mg/kg), or saline. Twenty-four hours later, rats�
Gabriele, Amanda; Packard, Mark G.
Long-Term Memory for a Common Object.
Five experiments investigated how completely and accurately adults remember the visual details of the common United States penny. Subjects had to draw a penny from unaided recall and select the correct representation of a penny. Performance was poor on all tasks. Implications for long-term memory models were discussed. (Author/RD)
Nickerson, Raymond S.; Adams, Marilyn Jager
Long Term Potentiation as a Mechanism for Learning and Memory
Directory of Open Access Journals (Sweden)
Full Text Available Since the 1970s when long term potentiation (LTP was introduced to the scientific world;several studies have been devoted to determining whether this phenomenon is naturally abasic mechanism of learning and memory in mammalian brains. However, plenty of evidenceconfirms that a LTP is inducible in the circuits involved in learning and memory; b commonreceptors and intracellular cascades are recruited in both memory and synaptic plasticityand c LTP and memory are similarly affected by many parameters such as: ligands, environmentalsignals, history of neuronal activity. Despite this, contradictory reports exist whichoppose the similarities between LTP and memory. In this paper we briefly introduce learning,memory and LTP, and argue relevant factors that possibly connect them. Ultimately, currentconsiderations lead one to conclude that the time is too early to judge clearly if LTP is a realmechanism of learning and memory.
Gholamali Hamidi
Binding actions and scenes in visual long-term memory.
How does visual long-term memory store representations of different entities (e.g., objects, actions, and scenes) that are present in the same visual event? Are the different entities stored as an integrated representation in memory, or are they stored separately? To address this question, we asked observers to view a large number of events; in each event, an action was performed within a scene. Afterward, the participants were shown pairs of action-scene sets and indicated which of the two they had seen. When the task required recognizing the individual actions and scenes, performance was high (80%). Conversely, when the task required remembering which actions had occurred within which scenes, performance was significantly lower (59%). We observed this dissociation between memory for individual entities and memory for entity bindings across multiple testing conditions and presentation durations. These experiments indicate that visual long-term memory stores information about actions and information about scenes separately from one another, even when an action and scene were observed together in the same visual event. These findings also highlight an important limitation of human memory: Situations that require remembering actions and scenes as integrated events (e.g., eyewitness testimony) may be particularly vulnerable to memory errors. PMID:23653419
Urgolites, Zhisen Jiang; Wood, Justin N
Long-term memory in electricity prices: Czech market evidence
Digital Repository Infrastructure Vision for European Research (DRIVER)
We analyze long-term memory properties of hourly prices of electricity in the Czech Republic between 2009 and 2012. As the dynamics of the electricity prices is dominated by cycles -- mainly intraday and daily -- we opt for the detrended fluctuation analysis, which is well suited for such specific series. We find that the electricity prices are non-stationary but strongly mean-reverting which distinguishes them from other financial assets which are usually characterized as u...
Kristoufek, Ladislav; Lunackova, Petra
Biasing perception by spatial long-term memory.
Digital Repository Infrastructure Vision for European Research (DRIVER)
Human perception is highly flexible and adaptive. Selective processing is tuned dynamically according to current task goals and expectations to optimize behavior. Arguably, the major source of our expectations about events yet to unfold is our past experience; however, the ability of long-term memories to bias early perceptual analysis has remained untested. We used a noninvasive method with high temporal resolution to record neural activity while human participants detected visual targets th...
Long-Term Memory for Affiliates in Ravens
Digital Repository Infrastructure Vision for European Research (DRIVER)
Complex social life requires individuals to recognize and�remember group members [1] and, within those, to distinguish affiliates from nonaffiliates. Whereas long-term individual recognition has been demonstrated in some nonhuman animals [2�5], memory for the relationship valence to former group members has received little attention. Here we show that adult, pair-housed ravens not only respond differently to the playback of calls from previous group members and unfamiliar conspecifics but ...
Boeckle, Markus; Bugnyar, Thomas
Shared component processes in working memory and long-term memory : Insights from functional brain imaging
Digital Repository Infrastructure Vision for European Research (DRIVER)
Marklund, P. (2004). Shared component processes in working memory and long-term memory: Insights from functional brain imaging. Department of Psychology, Ume� University, S-901 87 Ume� SwedenRecent findings from functional neuroimaging studies have shown pronounced similarities in the functional brain activity patterns associated with tests of various cognitive functions. This thesis investigates shared component processes in working memory and declarative long-term memory. Study 1 showed a...
Marklund, Petter
Hippocampus-dependent strengthening of targeted memories via reactivation during sleep in humans.
Recent accumulating evidence in animals and humans has shown that memory strengthening occurs, at least partially, during sleep and relies on the covert reactivation of individual memory episodes. However, it remains to be determined whether the hippocampus critically promotes memory consolidation via the reactivation of individual memories during sleep. To investigate the hippocampal-dependent nature of this phenomenon in humans, we selected two groups of chronic temporal lobe epileptic (TLE) patients with selective unilateral (TLE+UHS) or bilateral (TLE+BHS) hippocampal sclerosis and a group of matched healthy controls, and we requested them to learn the association of sounds cueing the appearance of words. On the basis of other similar behavioral paradigms in healthy populations, sounds that cued only half of the learned memories were presented again during the slow-wave sleep stage (SWS) at night, thus promoting memory reactivation of a select set of encoded episodes. A memory test administered on the subsequent day showed that the strengthening of reactivated memories was observed only in the control subjects and TLE+UHS patients. Importantly, the amount of memory strengthening was predicted by the volume of spared hippocampus. Thus, the greater the structural integrity of the hippocampus, the higher the degree of memory benefit driven by memory reactivation. Finally, sleep-specific neurophysiological responses, such as spindles and slow waves, differed between the sample groups, and the spindle density during SWS predicted the degree of memory benefit observed on day 2. Taken together, these findings demonstrate that the hippocampus plays a crucial role in the consolidation of memories via covert reactivation during sleep. PMID:24012316
Fuentemilla, Llu�s; Mir�, J�lia; Ripoll�s, Pablo; Vil�-Ball�, Adri�; Juncadella, Montserrat; Casta�er, Sara; Salord, Neus; Monasterio, Carmen; Falip, Merc�; Rodr�guez-Fornells, Antoni
Working Memory, Long-Term Memory, and Medial Temporal Lobe Function
Early studies of memory-impaired patients with medial temporal lobe (MTL) damage led to the view that the hippocampus and related MTL structures are involved in the formation of long-term memory and that immediate memory and working memory are independent of these structures. This traditional idea has recently been revisited. Impaired performance�
Jeneson, Annette; Squire, Larry R.
Long-term memory of individual identity in ant queens
DEFF Research Database (Denmark)
Remembering individual identities is part of our own everyday social life. Surprisingly, this ability has recently been shown in two social insects. While paper wasps recognize each other individually through their facial markings, the ant, Pachycondyla villosa, uses chemical cues. In both species, individual recognition is adaptive since it facilitates the maintenance of stable dominance hierarchies among individuals, and thus reduces the cost of conflict within these small societies. Here, we investigated individual recognition in Pachycondyla ants by quantifying the level of aggression between pairs of familiar or unfamiliar queens over time. We show that unrelated founding queens of P. villosa and Pachycondyla inversa store information on the individual identity of other queens and can retrieve it from memory after 24h of separation. Thus, we have documented for the first time that long-term memory of individual identity is present and functional in ants. This novel finding represents an advance in our understanding of the mechanism determining the evolution of cooperation among unrelated individuals.
Dreier, Stéphanie Agnès Jeanine; Van Zweden, Jelle Stijn
DNA methylation mediates the discriminatory power of associative long-term memory in honeybees
Digital Repository Infrastructure Vision for European Research (DRIVER)
Memory is created by several interlinked processes in the brain, some of which require long-term gene regulation. Epigenetic mechanisms are likely candidates for regulating memory-related genes. Among these, DNA methylation is known to be a long lasting genomic mark and may be involved in the establishment of long-term memory. Here we demonstrate that DNA methyltransferases, which induce and maintain DNA methylation, are involved in a particular aspect of associative long-term memory formatio...
DNA Methylation Mediates the Discriminatory Power of Associative Long-Term Memory in Honeybees
Digital Repository Infrastructure Vision for European Research (DRIVER)
Memory is created by several interlinked processes in the brain, some of which require long-term gene regulation. Epigenetic mechanisms are likely candidates for regulating memory-related genes. Among these, DNA methylation is known to be a long lasting genomic mark and may be involved in the establishment of long-term memory. Here we demonstrate that DNA methyltransferases, which induce and maintain DNA methylation, are involved in a particular aspect of associative long-term memory formatio...
Exploring the interaction between working memory and long-term memory: Evidence for the workspace model
Digital Repository Infrastructure Vision for European Research (DRIVER)
There is a large range of models of working memory, each with different scopes and emphases. Current interest focuses strongly on the interaction of working memory with long-term memory, as it has become clear that models of working memory alone are incapable of capturing some of our complex cognitive abilities. Most models have contrasting views on how this interaction is implemented. In this thesis, three classes of models are defined, each proposing a different type of interaction. The fir...
Meulen, Marian
Musical and Verbal Memory in Alzheimer's Disease: A Study of Long-Term and Short-Term Memory
Musical memory was tested in Alzheimer patients and in healthy older adults using long-term and short-term memory tasks. Long-term memory (LTM) was tested with a recognition procedure using unfamiliar melodies. Short-term memory (STM) was evaluated with same/different judgment tasks on short series of notes. Musical memory was compared to verbal�
Menard, Marie-Claude; Belleville, Sylvie
Impaired long-term potentiation and long-term memory deficits in xCT-deficient sut mice
Digital Repository Infrastructure Vision for European Research (DRIVER)
xCT is the functional subunit of the cystine/glutamate antiporter system xc?, which exchanges intracellular glutamate with extracellular cystine. xCT has been reported to play roles in the maintenance of intracellular redox and ambient extracellular glutamate, which may affect neuronal function. To assess a potential role of xCT in the mouse hippocampus, we performed fear conditioning and passive avoidance for long-term memories and examined hippocampal synaptic plasticity in wild-type mice...
Li, Yan; Tan, Zhibing; Li, Zhigang; Sun, Zhongsheng; Duan, Shumin; Li, Wei
The Role of the ? GABA(A) Receptor in Ovarian Cycle-Linked Changes in Hippocampus-Dependent Learning and Memory.
The ? subunit of the GABAAR is highly expressed in the dentate gyrus of the hippocampus where it mediates a tonic extrasynaptic inhibitory current that is sensitive to neurosteroids. In female mice, the expression level of the ? subunit within the dentate gyrus is elevated in the diestrous relative to estrous phase of the estrous cycle. Previous work in our lab found that female ?-GABAAR KO mice showed enhanced hippocampus-dependent trace but normal hippocampus-independent delay fear conditioning. Wild-type females in this study showed a wide range of freezing levels, whereas ?-GABAAR KO mice expressed only high levels of fear. We hypothesized that the variability in the wild-type mice may have been due to estrous cycle-mediated changes in the expression of the ?-GABAAR, with low levels of freezing in mice that were in the diestrous phase when dentate gyrus tonic inhibition is high. In the present study we tested this hypothesis by utilizing contextual, delay, and trace fear conditioning protocols in mice that were trained and tested in either the diestrous or estrous phases. Consistent with our hypothesis, we found a significant impairment of hippocampus-dependent learning and memory during diestrus relative to estrus in wild-type mice and this impairment was absent in ?-GABAAR mice. These findings argue that the ?-GABAAR plays an important role in estrous cycle-mediated fluctuations in hippocampus-dependent learning and memory. PMID:24667980
Cushman, Jesse D; Moore, Mellissa D; Olsen, Richard W; Fanselow, Michael S
Early calcium increase triggers the formation of olfactory long-term memory in honeybees
Background Synaptic plasticity associated with an important wave of gene transcription and protein synthesis underlies long-term memory processes. Calcium (Ca2+) plays an important role in a variety of neuronal functions and indirect evidence suggests that it may be involved in synaptic plasticity and in the regulation of gene expression correlated to long-term memory formation. The aim of this study was to determine whether Ca2+ is necessary and sufficient for inducing long-term memory formation. A suitable model to address this question is the Pavlovian appetitive conditioning of the proboscis extension reflex in the honeybee Apis mellifera, in which animals learn to associate an odor with a sucrose reward. Results By modulating the intracellular Ca2+ concentration ([Ca2+]i) in the brain, we show that: (i) blocking [Ca2+]i increase during multiple-trial conditioning selectively impairs long-term memory performance; (ii) conversely, increasing [Ca2+]i during single-trial conditioning triggers long-term memory formation; and finally, (iii) as was the case for long-term memory produced by multiple-trial conditioning, enhancement of long-term memory performance induced by a [Ca2+]i increase depends on de novo protein synthesis. Conclusion Altogether our data suggest that during olfactory conditioning Ca2+ is both a necessary and a sufficient signal for the formation of protein-dependent long-term memory. Ca2+ therefore appears to act as a switch between short- and long-term storage of learned information.
Perisse, Emmanuel; Raymond-Delpech, Valerie; Neant, Isabelle; Matsumoto, Yukihisa; Leclerc, Catherine; Moreau, Marc; Sandoz, Jean-Christophe
The Neural Substrates of Recognition Memory for Verbal Information: Spanning the Divide between Short- and Long-term Memory
Digital Repository Infrastructure Vision for European Research (DRIVER)
One of the classic categorical divisions in the history of memory research is that between short-term and long-term memory. Indeed, because memory for the immediate past (a few seconds) and memory for the relatively more remote past (several seconds and beyond) are assumed to rely on distinct neural systems, more often than not, memory research has focused either on short- (or �working memory�) or on long-term memory. Using an auditory�verbal continuous recognition paradigm designed for...
Buchsbaum, Bradley R.; Padmanabhan, Aarthi; Berman, Karen Faith
Directory of Open Access Journals (Sweden)
Full Text Available The aim of this study was to compare the Short Term Memory and Long Term Memory of Athlete and non Athlete. One hundred college boys (50 Athlete participated in inter-college tournament and 50 non Athlete from different colleges of north 24 district in West Bengal were considered for this study whose age range between 22 to 25 years. Only, Short Term and Long Term memory were measured for this study. Standard questionnaires were used for this study. The statistical 't' test was applied to investigate the existence of significant difference in Short Term Memory and Long Term Memory between Athlete and non Athlete. In conclusion Athlete performed better in the both tests i.e. Short Term Memory and Long Term Memory in comparison to non Athlete and the difference was statistically significant. Exercise not only gives healthy life style but also improve memory function. so regular exercise is strongly recommended.
Short- and long-term memory: differential involvement of neurotransmitter systems and signal transduction cascades
Directory of Open Access Journals (Sweden)
Full Text Available Since William James (1890 first distinguished primary from secondary memory, equivalent to short- and long-term memory, respectively, it has been assumed that short-term memory processes are in charge of cognition while long-term memory is being consolidated. From those days a major question has been whether short-term memory is merely a initial phase of long-term memory, or a separate phenomena. Recent experiments have shown that many treatments with specific molecular actions given into the hippocampus and related brain areas after one-trial avoidance learning can effectively cancel short-term memory without affecting long-term memory formation. This shows that short-term memory and long-term memory involve separate mechanisms and are independently processed. Other treatments, however, influence both memory types similarly, suggesting links between both at the receptor and at the post-receptor level, which should not be surprising as they both deal with nearly the same sensorimotor representations. This review examines recent advances in short- and long-term memory mechanisms based on the effect of intra-hippocampal infusion of drugs acting upon neurotransmitter and signal transduction systems on both memory types.
Short- and long-term memory: differential involvement of neurotransmitter systems and signal transduction cascades
Scientific Electronic Library Online (English)
Full Text Available SciELO Brazil | Language: English Abstract in english Since William James (1890) first distinguished primary from secondary memory, equivalent to short- and long-term memory, respectively, it has been assumed that short-term memory processes are in charge of cognition while long-term memory is being consolidated. From those days a major question has be [...] en whether short-term memory is merely a initial phase of long-term memory, or a separate phenomena. Recent experiments have shown that many treatments with specific molecular actions given into the hippocampus and related brain areas after one-trial avoidance learning can effectively cancel short-term memory without affecting long-term memory formation. This shows that short-term memory and long-term memory involve separate mechanisms and are independently processed. Other treatments, however, influence both memory types similarly, suggesting links between both at the receptor and at the post-receptor level, which should not be surprising as they both deal with nearly the same sensorimotor representations. This review examines recent advances in short- and long-term memory mechanisms based on the effect of intra-hippocampal infusion of drugs acting upon neurotransmitter and signal transduction systems on both memory types.
Subregion-Specific p300 Conditional Knock-Out Mice Exhibit Long-Term Memory Impairments
Histone acetylation plays a critical role during long-term memory formation. Several studies have demonstrated that the histone acetyltransferase (HAT) CBP is required during long-term memory formation, but the involvement of other HAT proteins has not been extensively investigated. The HATs CBP and p300 have at least 400 described interacting�
Oliveira, Ana M. M.; Estevez, Marcel A.; Hawk, Joshua D.; Grimes, Shannon; Brindle, Paul K.; Abel, Ted
A Revised Model of Short-Term Memory and Long-Term Learning of Verbal Sequences
The interaction between short- and long-term memory is studied within a model in which phonemic and (temporal) contextual information have separate influences on immediate verbal serial recall via connections with short- and long-term plasticity [Burgess, N., & Hitch, G.J. (1999). Memory for serial order: a network model of the phonological loop�
Burgess, Neil; Hitch, Graham J.
They Saw a Movie: Long-Term Memory for an Extended Audiovisual Narrative
We measured long-term memory for a narrative film. During the study session, participants watched a 27-min movie episode, without instructions to remember it. During the test session, administered at a delay ranging from 3 h to 9 mo after the study session, long-term memory for the movie was probed using a computerized questionnaire that assessed�
Furman, Orit; Dorfman, Nimrod; Hasson, Uri; Davachi, Lila; Dudai, Yadin
Learning-facilitated long-term depression and long-term potentiation at mossy fiber�CA3 synapses requires activation of ?-adrenergic receptors
Digital Repository Infrastructure Vision for European Research (DRIVER)
Learning-facilitated plasticity refers to hippocampal synaptic plasticity that is facilitated by novel spatial learning events. Both long-term potentiation (LTP) and long-term depression (LTD) are facilitated by novel hippocampus-dependent learning. This has important ramifications for our understanding of how the hippocampus encodes memory. One structure that is rarely studied in vivo, but is believed to be crucially important for working and long-term memory processing is the hippocampal CA...
Hagena, Hardy; Manahan-vaughan, Denise
Short-term memory to long-term memory transition in a nanoscale memristor.
"Memory" is an essential building block in learning and decision-making in biological systems. Unlike modern semiconductor memory devices, needless to say, human memory is by no means eternal. Yet, forgetfulness is not always a disadvantage since it releases memory storage for more important or more frequently accessed pieces of information and is thought to be necessary for individuals to adapt to new environments. Eventually, only memories that are of significance are transformed from short-term memory into long-term memory through repeated stimulation. In this study, we show experimentally that the retention loss in a nanoscale memristor device bears striking resemblance to memory loss in biological systems. By stimulating the memristor with repeated voltage pulses, we observe an effect analogous to memory transition in biological systems with much improved retention time accompanied by additional structural changes in the memristor. We verify that not only the shape or the total number of stimuli is influential, but also the time interval between stimulation pulses (i.e., the stimulation rate) plays a crucial role in determining the effectiveness of the transition. The memory enhancement and transition of the memristor device was explained from the microscopic picture of impurity redistribution and can be qualitatively described by the same equations governing biological memories. PMID:21861506
Chang, Ting; Jo, Sung-Hyun; Lu, Wei
Long-term Memory and Volatility Clustering in Daily and High-frequency Price Changes
We study the long-term memory in diverse stock market indices and foreign exchange rates using the Detrended Fluctuation Analysis(DFA). For all daily and high-frequency market data studied, no significant long-term memory property is detected in the return series, while a strong long-term memory property is found in the volatility time series. The possible causes of the long-term memory property are investigated using the return data filtered by the AR(1) model, reflecting the short-term memory property, and the GARCH(1,1) model, reflecting the volatility clustering property, respectively. Notably, we found that the memory effect in the AR(1) filtered return and volatility time series remains unchanged, while the long-term memory property either disappeared or diminished significantly in the volatility series of the GARCH(1,1) filtered data. We also found that in the high-frequency data the long-term memory property may be generated by the volatility clustering as well as higher autocorrelation. Our results i...
Oh, G J; Um, C J; Kim, Seunghwann; Oh, GabJin; Um, Cheol-Jun
Early calcium increase triggers the formation of olfactory long-term memory in honeybees
Directory of Open Access Journals (Sweden)
Full Text Available Abstract Background Synaptic plasticity associated with an important wave of gene transcription and protein synthesis underlies long-term memory processes. Calcium (Ca2+ plays an important role in a variety of neuronal functions and indirect evidence suggests that it may be involved in synaptic plasticity and in the regulation of gene expression correlated to long-term memory formation. The aim of this study was to determine whether Ca2+ is necessary and sufficient for inducing long-term memory formation. A suitable model to address this question is the Pavlovian appetitive conditioning of the proboscis extension reflex in the honeybee Apis mellifera, in which animals learn to associate an odor with a sucrose reward. Results By modulating the intracellular Ca2+ concentration ([Ca2+]i in the brain, we show that: (i blocking [Ca2+]i increase during multiple-trial conditioning selectively impairs long-term memory performance; (ii conversely, increasing [Ca2+]i during single-trial conditioning triggers long-term memory formation; and finally, (iii as was the case for long-term memory produced by multiple-trial conditioning, enhancement of long-term memory performance induced by a [Ca2+]i increase depends on de novo protein synthesis. Conclusion Altogether our data suggest that during olfactory conditioning Ca2+ is both a necessary and a sufficient signal for the formation of protein-dependent long-term memory. Ca2+ therefore appears to act as a switch between short- and long-term storage of learned information.
Matsumoto Yukihisa
Lateral Habenula determines long-term storage of aversive memories
The Lateral Habenula (LHb) is a small brain structure that codifies negative motivational value and has been related to major depression. It has been shown recently that LHb activation is sufficient to induce aversive associative learning; however the key question about whether LHb activation is required for an aversive memory to be formed has not been addressed. In this article we studied the function of the LHb in memory formation using the Inhibitory Avoidance task (IA). We found that LHb inactivation during IA training does not disrupt memory when assessed 24 h after, but abolishes it 7 days later, indicating that LHb activity during memory acquisition is not necessary for memory formation, but regulates its temporal stability. These effects suggest that LHb inactivation modifies subjective perception of the training experience.
Tomaiuolo, Micol; Gonzalez, Carolina; Medina, Jorge H.; Piriz, Joaquin
Lateral Habenula determines long-term storage of aversive memories.
Directory of Open Access Journals (Sweden)
Full Text Available The Lateral Habenula (LHb is a small brain structure that codifies negative motivational value and has been related to major depression. It has been shown recently that LHb activation is sufficient to induce aversive associative learning; however the key question about whether LHb activation is required for an aversive memory to be formed has not been addressed. In this article we studied the function of the LHb in memory formation using the Inhibitory Avoidance task (IA. We found that LHb inactivation during IA training does not disrupt memory when assessed 24 hours after, but abolishes it 7 days later, indicating that LHb activity during memory acquisition is not necessary for memory formation, but regulates its temporal stability. These effects suggest that LHb inactivation modifies subjective perception of the training experience.
Debra, a protein mediating lysosomal degradation, is required for long-term memory in Drosophila.
A central goal of neuroscience is to understand how neural circuits encode memory and guide behavior changes. Many of the molecular mechanisms underlying memory are conserved from flies to mammals, and Drosophila has been used extensively to study memory processes. To identify new genes involved in long-term memory, we screened Drosophila enhancer-trap P(Gal4) lines showing Gal4 expression in the mushroom bodies, a specialized brain structure involved in olfactory memory. This screening led to the isolation of a memory mutant that carries a P-element insertion in the debra locus. debra encodes a protein involved in the Hedgehog signaling pathway as a mediator of protein degradation by the lysosome. To study debra's role in memory, we achieved debra overexpression, as well as debra silencing mediated by RNA interference. Experiments conducted with a conditional driver that allowed us to specifically restrict transgene expression in the adult mushroom bodies led to a long-term memory defect. Several conclusions can be drawn from these results: i) debra levels must be precisely regulated to support normal long-term memory, ii) the role of debra in this process is physiological rather than developmental, and iii) debra is specifically required for long-term memory, as it is dispensable for earlier memory phases. Drosophila long-term memory is the only long-lasting memory phase whose formation requires de novo protein synthesis, a process underlying synaptic plasticity. It has been shown in several organisms that regulation of proteins at synapses occurs not only at translation level of but also via protein degradation, acting in remodeling synapses. Our work gives further support to a role of protein degradation in long-term memory, and suggests that the lysosome plays a role in this process. PMID:21991383
Kottler, Benjamin; Lampin-Saint-Amaux, Aur�lie; Comas, Daniel; Preat, Thomas; Goguel, Val�rie
Transient impairment of hippocampus-dependent learning and memory in relatively low-dose of acute radiation syndrome is associated with inhibition of hippocampal neurogenesis
International Nuclear Information System (INIS)
Neurogenesis in the adult hippocampus, which occurs constitutively, is vulnerable to ionizing radiation. In the relatively low-dose exposure of acute radiation syndrome (ARS), the change in the adult hippocampal function is poorly understood. This study analyzed the changes in apoptotic cell death and neurogenesis in the DGs of hippocampi from adult ICR mice with single whole-body gamma-irradiation using the TdT-mediated dUTP-biotin nick end-labeling (TUNEL) method and immunohistochemical markers of neurogenesis, Ki-67 and doublecortin (DCX). In addition, the hippocampus-dependent learning and memory tasks after single whole-body gamma-irradiation were examined in order to evaluate the hippocampus-related behavioral dysfunction in the relatively low-dose exposure of ARS. The number of TUNEL-positive apoptotic nuclei in the dentate gyrus (DG) was increased 6-12 h after acute gamma-irradiation (a single dose of 0.5 to 4 Gy). In contrast, the number of Ki-67- and DCX-positive cells began to decrease significantly 6 h postirradiation, reaching its lowest level 24 h after irradiation. The level of Ki-67 and DCX immunoreactivity decreased in a dose-dependent manner within the range of irradiation applied (0-4 Gy). In passive avoidance and object recognition memory test, the mice trained 1 day after acute irradiation (2 Gy) showed significant memory deficits, compared with the sham controls. In conclusion, the pattern of the hippocampus-dependent memory dysfunction is consistent with the change in neurogenesis after acute irradiation. It is suggested that a relatively low dose of ARS in adult ICR mice is sufficiently detrimental to interrupt the functioning of the hippocampus, including learning and memory, possibly through the inhibition of neurogenesis. (author)
Endogenous BDNF Is Required for Long-Term Memory Formation in the Rat Parietal Cortex
Information storage in the brain is a temporally graded process involving different memory phases as well as different structures in the mammalian brain. Cortical plasticity seems to be essential to store stable long-term memories, although little information is available at the moment regarding molecular and cellular events supporting memory�
Alonso, Mariana; Bekinschtein, Pedro, Cammarota, Martin; Vianna, Monica R. M.; Izquierdo, Ivan; Medina, Jorge H.
Debra, a Protein Mediating Lysosomal Degradation, Is Required for Long-Term Memory in Drosophila
Digital Repository Infrastructure Vision for European Research (DRIVER)
A central goal of neuroscience is to understand how neural circuits encode memory and guide behavior changes. Many of the molecular mechanisms underlying memory are conserved from flies to mammals, and Drosophila has been used extensively to study memory processes. To identify new genes involved in long-term memory, we screened Drosophila enhancer-trap P(Gal4) lines showing Gal4 expression in the mushroom bodies, a specialized brain structure involved in olfactory memory. This screening led t...
Kottler, Benjamin; Lampin-saint-amaux, Aure?lie; Comas, Daniel; Preat, Thomas; Goguel, Vale?rie
Fatty-Acid Binding Proteins Modulate Sleep and Enhance Long-Term Memory Consolidation in Drosophila
Digital Repository Infrastructure Vision for European Research (DRIVER)
Sleep is thought to be important for memory consolidation, since sleep deprivation has been shown to interfere with memory processing. However, the effects of augmenting sleep on memory formation are not well known, and testing the role of sleep in memory enhancement has been limited to pharmacological and behavioral approaches. Here we test the effect of overexpressing the brain-type fatty acid binding protein (Fabp7) on sleep and long-term memory (LTM) formation in Drosophila melanogaster. ...
Gerstner, Jason R.; Vanderheyden, William M.; Shaw, Paul J.; Landry, Charles F.; Yin, Jerry C. P.
Natural variation in long-term memory formation among Nasonia parasitic wasp species.
Closely related species of parasitic wasps can differ substantially in memory dynamics. In this study we demonstrate differences in the number of conditioning trials required to form long-term memory between the closely related parasitic wasp species Nasonia vitripennis and Nasonia giraulti (Hymenoptera: Pteromalidae). A single conditioning trial, in which a female wasp associates an odour with the reward of finding a host, results in the formation of transcription-dependent long-term memory in N. vitripennis, whereas N. giraulti requires spaced training to do so. Memory formation does not depend on the type of reward: oviposition, which was hypothesized to be a 'larger' reward results in similar memory retention as host feeding in both Nasonia species. There are several genetic and genomic tools available for Nasonia species to identify genetic mechanisms that underlie the observed variation in the number of trials required to form long-term memory. PMID:24607391
Hoedjes, Katja M; Smid, Hans M
Early calcium increase triggers the formation of olfactory long-term memory in honeybees
Digital Repository Infrastructure Vision for European Research (DRIVER)
Abstract Background Synaptic plasticity associated with an important wave of gene transcription and protein synthesis underlies long-term memory processes. Calcium (Ca2+) plays an important role in a variety of neuronal functions and indirect evidence suggests that it may be involved in synaptic plasticity and in the regulation of gene expression correlated to long-term memory formation. The aim of this study was to determine whether Ca2+ is necessary an...
Long-term consequences of subarachnoid hemorrhage: examining working memory.
Working memory impairments are prevalent among survivors of aneurysmal subarachnoid hemorrhage (SAH), but few studies have examined specifically these impairments. Such an examination is important because working memory processes are vital for daily cognitive functioning. In the current study, patients with SAH and healthy control participants were administered the word-span and alpha-span test - experimental tests of working memory. In the word-span test, participants recalled increasingly longer word-lists, requiring the maintenance of information in mind. In the alpha-span test, participants recalled the word-lists in alphabetical order, requiring both the maintenance and manipulation of information. Patients with SAH were no different from healthy controls on a battery of standard neuropsychological measures or on the word-span test. They were, however, significantly impaired on the alpha-span test, suggesting a deficit in the manipulation components of working memory. That is, impairment resulting from SAH is present when a working memory task requires additional executive processing demands. This deficit in patients with SAH does not appear to be influenced by aneurysm location, suggesting that some of the effects of SAH on cognition are from diffuse rather than focal pathology; however, a larger sample size is needed to reinforce this claim. PMID:23871092
Sheldon, Signy; Macdonald, R Loch; Cusimano, Michael; Spears, Julian; Schweizer, Tom A
Post-Training Intrahippocampal Inhibition of Class I Histone Deacetylases Enhances Long-Term Object-Location Memory
Long-term memory formation involves covalent modification of the histone proteins that package DNA. Reducing histone acetylation by mutating histone acetyltransferases impairs long-term memory, and enhancing histone acetylation by inhibiting histone deacetylases (HDACs) improves long-term memory. Previous studies using HDAC inhibitors to enhance�
Hawk, Joshua D.; Florian, Cedrick; Abel, Ted
Long term memory profile of disorders associated with dysregulation of the RAS-MAPK signaling cascade.
In the present study we evaluated long term memory in twenty individuals with molecularly confirmed diagnosis of Noonan syndrome and LEOPARD syndrome, two disorders caused by mutations in genes coding transducers participating in the RAS-MAPK signaling cascade. The profile of explicit long term memory abilities was investigated using PROMEA, which includes a battery of tests specifically developed to assess memory and learning in verbal, visual and spatial domains. Ten individuals (50%) had impaired (?5th percentile) or below average (?15th percentile) performance on a delayed verbal free recall memory task, four (20%) on a delayed visual recognition memory task, and only one (5%) on a delayed spatial recognition memory task. Our data suggest that dysregulation of the RAS-MAPK cascade may be associated with a pattern of reduced verbal recall memory performance but relative sparing of visual and spatial recognition memory. PMID:21274610
Alfieri, Paolo; Cesarini, Laura; Mallardi, Maria; Piccini, Giorgia; Caciolo, Cristina; Leoni, Chiara; Mirante, Nadia; Pantaleoni, Francesca; Digilio, Maria Cristina; Gambardella, Maria Luigia; Tartaglia, Marco; Vicari, Stefano; Mercuri, Eugenio; Zampino, Giuseppe
Aging and long-term memory for emotionally valenced events.
In 2008, 1103 ardent Boston Red Sox fans answered questions about their team's 2003 loss and 2004 win in baseball championship games with archrival New York Yankees. Contrary to predictions based on socioemotional selectivity theory, there were no significant interactions of age and event valence for accuracy in remembering event details, or for self-reported subjective vividness and rehearsal of the memories. Fans 65 years and older tended to remember feeling only sad about the 2003 loss, whereas fans 25 years and under tended to remember feeling both sad and angry. Individuals may remember emotional feelings based on remembered goals about an event. PMID:22888956
Breslin, Carolyn W; Safer, Martin A
PKG-Mediated MAPK Signaling Is Necessary for Long-Term Operant Memory in "Aplysia"
Signaling pathways necessary for memory formation, such as the mitogen-activated protein kinase (MAPK) pathway, appear highly conserved across species and paradigms. Learning that food is inedible (LFI) represents a robust form of associative, operant learning that induces short- (STM) and long-term memory (LTM) in "Aplysia." We investigated the�
Michel, Maximilian; Green, Charity L.; Eskin, Arnold; Lyons, Lisa C.
Two Waves of Transcription Are Required for Long-Term Memory in the Honeybee
Storage of information into long-term memory (LTM) usually requires at least two waves of transcription in many species. However, there is no clear evidence of this phenomenon in insects, which are influential models for memory studies. We measured retention in honeybees after injecting a transcription inhibitor at different times before and after�
Lefer, Damien; Perisse, Emmanuel; Hourcade, Benoit; Sandoz, JeanChristophe; Devaud, Jean-Marc
What are the differences between long-term, short-term, and working memory?
Digital Repository Infrastructure Vision for European Research (DRIVER)
In the recent literature there has been considerable confusion about the three types of memory: long-term, short-term, and working memory. This chapter strives to reduce that confusion and makes up-to-date assessments of these types of memory. Long- and short-term memory could differ in two fundamental ways, with only short-term memory demonstrating (1) temporal decay and (2) chunk capacity limits. Both properties of short-term memory are still controversial but the current literature is rath...
Cowan, Nelson
Memory Distortion in Alzheimer's Disease: Deficient Monitoring of Short and Long-term Memory
Objective This study measured distortions of memory during short-term memory (STM) and long-term memory (LTM) versions of a semantically-associated word list learning paradigm. Performance of patients with mild-to-moderate Alzheimer�s disease (AD; MMSE ? 16) was compared to performance of age-matched, healthy older adult participants. Method In a STM version of the Deese-Roediger-McDermott (DRM) task, participants viewed four-word lists and were prompted for recall after a brief interval. The LTM task tested recall memory for 12-word lists. Results Compared to the healthy group, the AD participants show greater impairment on the LTM task than on the STM task, although veridical recall is significantly reduced on both tasks. Furthermore, on both memory tasks: a) Participants with AD generate more nonsemantic intrusions than healthy older adult participants; b) semantic intrusion rate, when computed as a proportion of total recall, does not differ between groups. Notably, nonsemantic intrusions are consistently high for AD participants across both STM and LTM despite a marked difference in recall accuracy (65% and 23%, respectively). Conclusions STM impairment with some preserved semantic processing is evident in AD. The extent and variety of intrusions reported by AD participants indicates a breakdown in their ability to monitor and constrain their recall responses, even within seconds of initial learning.
MacDuffie, Katherine E.; Atkins, Alexandra S.; Flegal, Kristin E.; Clark, Christopher M.; Reuter-Lorenz, Patricia A.
Long-term memory performance after surgical treatment of unilateral temporal lobe epilepsy (TLE).
Long-term cognitive and memory performance after surgical treatment of unilateral temporal lobe epilepsy (TLE) was investigated in a series of 98 patients. Neuropsychological evaluation was performed preoperatively and after one and three years postoperatively. Fifty-eight patients (59%) became seizure-free (Engel's class I). Verbal learning and memory declined in long-term follow-up in both left and right TLE groups. Visual memory remained stable. Ongoing postoperative seizures were related to decline in the immediate recall of logical prose, and postoperative seizure-freedom to improvement in verbal fluency in patients with left TLE. There was significant variability in the individual postoperative long-term memory performance. Left side of surgery, better baseline performance and older age at surgery were identified as risk factors for individual decline in delayed verbal memory. Selected patients undergoing surgery for drug-resistant TLE are at risk for significant postoperative memory decline especially after left temporal lobe surgery. Preoperative counseling and long-term follow-up of cognitive performance in individual patients is recommended. Additionally, more accurate predictors of individual postoperative memory performance would be needed. PMID:24953384
Jutila, Leena; Aiki�, Marja; Immonen, Arto; Mervaala, Esa; Alafuzoff, Irina; K�lvi�inen, Reetta
Astrocyte-neuron lactate transport is required for long-term memory formation
Digital Repository Infrastructure Vision for European Research (DRIVER)
We report that in the rat hippocampus learning leads to a significant increase in extracellular lactate levels, which derive from glycogen, an energy reserve selectively localized in astrocytes. Astrocytic glycogen breakdown and lactate release are essential for long-term but not short-term memory formation, and for the maintenance of long-term potentiation (LTP) of synaptic strength elicited in-vivo. Disrupting the expression of the astrocytic lactate transporters monocarboxylate transporter...
Suzuki, Akinobu; Stern, Sarah A.; Bozdagi, Ozlem; Huntley, George W.; Walker, Ruth H.; Magistretti, Pierre J.; Alberini, Cristina M.
Flavonoid fisetin promotes ERK-dependent long-term potentiation and enhances memory
Digital Repository Infrastructure Vision for European Research (DRIVER)
Small molecules that activate signaling pathways used by neurotrophic factors could be useful for treating CNS disorders. Here we show that the flavonoid fisetin activates ERK and induces cAMP response element-binding protein (CREB) phosphorylation in rat hippocampal slices, facilitates long-term potentiation in rat hippocampal slices, and enhances object recognition in mice. Together, these data demonstrate that the natural product fisetin can facilitate long-term memory, and therefore it ma...
Prefrontal dopamine and the dynamic control of human long-term memory
Digital Repository Infrastructure Vision for European Research (DRIVER)
Dopaminergic projections to the prefrontal cortex support higher-order cognitive functions, and are critically involved in many psychiatric disorders that involve memory deficits, including schizophrenia. The role of prefrontal dopamine in long-term memory, however, is still unclear. We used an imaging genetics approach to examine the hypothesis that dopamine availability in the prefrontal cortex selectively affects the ability to suppress interfering memories. Human participants were scanned...
Wimber, M.; Schott, B. H.; Wendler, F.; Seidenbecher, C. I.; Behnisch, G.; Macharadze, T.; Ba?uml, K-h T.; Richardson-klavehn, A.
The prion gene is associated with human long-term memory.
Human cognitive processes are highly variable across individuals and are influenced by both genetic and environmental factors. Although genetic variations affect short-term memory in humans, it is unknown whether genetic variability has also an impact on long-term memory. Because prion-like conformational changes may be involved in the induction of long-lasting synaptic plasticity, we examined the impact of single-nucleotide polymorphisms (SNPs) of the prion protein gene (PRNP) on long-term memory in healthy young humans. SNPs in the genomic region of PRNP were associated with better long-term memory performance in two independent populations with different educational background. Among the examined PRNP SNPs, the common Met129Val polymorphism yielded the highest effect size. Twenty-four hours after a word list-learning task, carriers of either the 129MM or the 129MV genotype recalled 17% more information than 129VV carriers, but short-term memory was unaffected. These results suggest a role for the prion protein in the formation of long-term memory in humans. PMID:15987701
Papassotiropoulos, Andreas; Wollmer, M Axel; Aguzzi, Adriano; Hock, Christoph; Nitsch, Roger M; de Quervain, Dominique J-F
Can we throw information out of visual working memory and does this leave informational residue in long-term memory?
Directory of Open Access Journals (Sweden)
Full Text Available Can we entirely erase a temporary memory representation from mind? This question has been addressed in several recent studies that tested the specific hypothesis that a representation can be erased from visual working memory based on a cue that indicated that the representation was no longer necessary for the task. In addition to behavioral results that are consistent with the idea that we can throw information out of visual working memory, recent neurophysiological recordings support this proposal. However, given the infinite capacity of long-term memory, it is unclear whether throwing a representation out of visual working memory really removes its effects on memory entirely. In this paper we advocate for an approach that examines our ability to erase memory representations from working memory, as well as possible traces that those erased representations leave in long-term memory.
The evidence for hippocampal long-term potentiation as a basis of memory for simple tasks
Digital Repository Infrastructure Vision for European Research (DRIVER)
Long-term potentiation (LTP) is the enhancement of postsynaptic responses for hours, days or weeks following the brief repetitive afferent stimulation of presynaptic afferents. It has been proposed many times over the last 30 years to be the basis of long-term memory. Several recent findings finally supported this hypothesis: a) memory formation of one-trial avoidance learning depends on a series of molecular steps in the CA1 region of the hippocampus almost identical to those of LTP in the s...
Iv�n Izquierdo; Mart�n Cammarota; Da Silva, Weber C.; Bevilaqua, Lia R. M.; Rossato, Janine I.; Bonini, Juliana S.; Pamela Mello; Fernando Benetti; Costa, Jaderson C.; Medina, Jorge H.
Prefrontal activity associated with working memory and episodic long-term memory.
Many recent neuroimaging studies have highlighted the role of prefrontal regions in the sustained maintenance and manipulation of information over short delays, or working memory (WM). In addition, neuroimaging findings have highlighted the role of prefrontal regions in the formation and retrieval of memories for events, or episodic long-term memory (LTM), but it remains unclear whether these regions are distinct from those that support WM. We used event-related functional magnetic resonance imaging (fMRI) to identify patterns of prefrontal activity associated with encoding and recognition during WM and LTM tasks performed by the same subjects. Results showed that the same bilateral ventrolateral prefrontal regions (at or near Brodmann's Areas [BA] 6, 44, 45, and 47) and dorsolateral prefrontal regions (BA 9/46) were engaged during encoding and recognition within the context of WM and LTM tasks. In addition, a region situated in the left anterior middle frontal gyrus (BA 10/46) was engaged during the recognition phases of the WM and LTM tasks. These results support the view that the same prefrontal regions implement reflective processes that support both WM and LTM. PMID:12457762
Ranganath, Charan; Johnson, Marcia K; D'Esposito, Mark
Long-term effects of neonatal single or multiple isoflurane exposures on spatial memory in rats
Directory of Open Access Journals (Sweden)
Full Text Available General anesthetics are neurotoxic to neonatal rodents and nonhuman primates. Neonatal exposure to general anesthetics has been associated with long-term cognitive deficits in animal models. Some data from humans are consistent with long-term deleterious effects of anesthetic exposure early in life on cognitive development, with multiple exposures to general anesthetics being particularly damaging. We sought to determine whether repeated exposure of neonatal rats to anesthesia was associated with long-term cognitive impairments and whether the magnitude of impairments was greater than that resulting from a single exposure. Male or female Long-Evans rat pups were exposed to 1.8% isoflurane for 2 hours on postnatal day (P 7, or for 2 hours each on P7, P10, and P13. Testing in a spatial working memory task began on P91. Rats that were repeatedly exposed to isoflurane were impaired relative to controls in the spatial working memory task. Male rats that received a single exposure to isoflurane showed an unexpected facilitation in spatial memory performance. These results support the hypothesis that multiple neonatal exposures to general anesthesia are associated with greater long-term cognitive impairment than a single exposure. The findings are congruent with human epidemiological studies reporting long-term cognitive impairments following multiple but not single general anesthetics early in life.
Making long-term memories in minutes: a time pattern from memory research in education
Directory of Open Access Journals (Sweden)
Full Text Available Memory systems select from environmental stimuli those to encode permanently. Repeated stimuli separated by timed spaces without stimuli can initiate Long-Term Potentiation (LTP and long-term memory (LTM encoding. These processes occur in time scales of minutes, and has been demonstrated in many species. This study reports on using a specific timed pattern of three repeated stimuli separated by ten-minute spaces drawn from both behavioural and laboratory studies of LTP and LTM encoding. A technique was developed based on this pattern to test whether encoding complex information into LTM in students was possible using the pattern within a very short time scale. In an educational context, stimuli were periods of highly compressed instruction, and spaces were created through 10 minute distractor activities. Spaced learning in this form was used as the only means of instruction for a national curriculum Biology course, and led to very rapid LTM encoding as measured by the high-stakes test for the course. Remarkably, learning at a greatly increased speed and in a pattern that included deliberate distraction produced significantly higher scores than random answers (p < 0.00001 and scores were not significantly different for experimental groups (one hour spaced learning and control groups (four months teaching. Thus learning per hour of instruction, as measured by the test, was significantly higher for the spaced learning groups (p < 0.00001. In a third condition, spaced learning was used to replace the end of course review for one of two examinations. Results showed significantly higher outcomes for the course using spaced learning (p < 0.0005. The implications of these findings and further areas for research are briefly considered.
Transcriptional regulation of long-term memory in the marine snail Aplysia
Directory of Open Access Journals (Sweden)
Full Text Available Abstract Whereas the induction of short-term memory involves only covalent modifications of constitutively expressed preexisting proteins, the formation of long-term memory requires gene expression, new RNA, and new protein synthesis. On the cellular level, transcriptional regulation is thought to be the starting point for a series of molecular steps necessary for both the initiation and maintenance of long-term synaptic facilitation (LTF. The core molecular features of transcriptional regulation involved in the long-term process are evolutionally conserved in Aplysia, Drosophila, and mouse, and indicate that gene regulation by the cyclic AMP response element binding protein (CREB acting in conjunction with different combinations of transcriptional factors is critical for the expression of many forms of long-term memory. In the marine snail Aplysia, the molecular mechanisms that underlie the storage of long-term memory have been extensively studied in the monosynaptic connections between identified sensory neuron and motor neurons of the gill-withdrawal reflex. One tail shock or one pulse of serotonin (5-HT, a modulatory transmitter released by tail shocks, produces a transient facilitation mediated by the cAMP-dependent protein kinase leading to covalent modifications in the sensory neurons that results in an enhancement of transmitter release and a strengthening of synaptic connections lasting minutes. By contrast, repeated pulses of 5-hydroxytryptamine (5-HT induce a transcription- and translation-dependent long-term facilitation (LTF lasting more than 24 h and trigger the activation of a family of transcription factors in the presynaptic sensory neurons including ApCREB1, ApCREB2 and ApC/EBP. In addition, we have recently identified novel transcription factors that modulate the expression of ApC/EBP and also are critically involved in LTF. In this review, we examine the roles of these transcription factors during consolidation of LTF induced by different stimulation paradigms.
Lee Yong-Seok
Late protein synthesis-dependent phases in CTA long-term memory: BDNF requirement
Directory of Open Access Journals (Sweden)
Full Text Available It has been proposed that long-term memory persistence requires a late protein synthesis-dependent phase, even many hours after memory acquisition. Brain-derived neurotrophic factor (BDNF is an essential protein synthesis product that has emerged as one of the most potent molecular mediators for long-term synaptic plasticity. Studies in the rat hippocampus have been shown that BDNF is capable to rescue the late-phase of long-term potentiation as well as the hippocampus-related long-term memory when protein synthesis was inhibited. Our previous studies on the insular cortex (IC, a region of the temporal cortex implicated in the acquisition and storage of conditioned taste aversion (CTA, have demonstrated that intracortical delivery of BDNF reverses the deficit in CTA memory caused by the inhibition of IC protein synthesis due to anisomycin administration during early acquisition. In this work, we first analyze whether CTA memory storage is protein synthesis dependent in different time-windows. We observed that CTA memory become sensible to protein synthesis inhibition 5 and 7 hours after acquisition. Then, we explore the effect of BDNF delivery (2 ?g/2 ?l per side in the IC during those late protein synthesis-dependent phases. Our results show that BDNF reverses the CTA memory deficit produced by protein synthesis inhibition in both phases. These findings support the notion that recurrent rounds of consolidation-like events take place in the neocortex for maintenance of CTA memory trace and that BDNF is an essential component of these processes.
Synaptic Scaling Enables Dynamically Distinct Short- and Long-Term Memory Formation
Digital Repository Infrastructure Vision for European Research (DRIVER)
Memory storage in the brain relies on mechanisms acting on time scales from minutes, for long-term synaptic potentiation, to days, for memory consolidation. During such processes, neural circuits distinguish synapses relevant for forming a longterm storage, which are consolidated, from synapses of short-term storage, which fade. How time scale integration and synaptic differentiation is simultaneously achieved remains unclear. Here we show that synaptic scaling � a slow process ...
Tetzlaff, Christian; Kolodziejski, Christoph; Timme, Marc; Tsodyks, Misha; Wo?rgo?tter, Florentin
The Antimetabolite ara-CTP Blocks Long-Term Memory of Conditioned Taste Aversion
Digital Repository Infrastructure Vision for European Research (DRIVER)
We examined the hypothesis that processes related to DNA recombination and repair are involved in learning and memory. Rats received intracerebroventricular (icv) infusions of the antimetabolite 1-beta-D-arabinofuranosylcytosine triphosphate (ara-CTP) or its precursor cytosine arabinoside (ara-C) 30 min prior to conditioned taste aversion (CTA) training. Both ara-CTP and ara-C caused significant impairments in long-term memory (LTM) of CTA. Control experiments indicate that the effect of ara-...
Wang, Jianpeng; Ren, Keqin; Pe?rez, Javier; Silva, Alcino J.; Pen?a Ortiz, Sandra
Transgenic Mice Expressing an Inhibitory Truncated Form of p300 Exhibit Long-Term Memory Deficits
The formation of many forms of long-term memory requires several molecular mechanisms including regulation of gene expression. The mechanisms directing transcription require not only activation of individual transcription factors but also recruitment of transcriptional coactivators. CBP and p300 are transcriptional coactivators that interact with�
Oliveira, Ana M. M.; Wood, Marcelo A.; McDonough, Conor B.; Abel, Ted
The Process of Retrieval from Very Long Term Memory. Technical Report No. 7801.
In an investigation into the process of retrieval from very long term memory, four subjects who had been out of high school from 4 to 19 years were asked to think aloud while attempting to recall the names of their high school classmates. The retrievals were found to be characterized by overshoot, systematic hypothesizing, fabrications, the�
Williams, Michael D.
The long-term memory analysis of industrial indices of the Chinese stock market
Energy Technology Data Exchange (ETDEWEB)
The main work of this paper is to apply the fractional market theory and time series analysis for analyzing various industrial indices of the Chinese stock market by rescaling range analysis. Hurst index and the long-term memory of price change in Chinese stock market are studied.
Yong, L [Renmin University of China, Information School (China); Department of Mathematics, Beijing 100872 (China)], E-mail: firstname.lastname@example.com
Automatic and Controlled Processing in Sentence Recall: The Role of Long-Term and Working Memory
Immediate serial recall is better for sentences than word lists presumably because of the additional support that meaningful material receives from long-term memory. This may occur automatically, without the involvement of attention, or may require additional attentionally demanding processing. For example, the episodic buffer model (Baddeley,�
Jefferies, E.; Lambon Ralph, M.A.; Baddeley, A.D.
Oscillatory power decreases and long-term memory: The information via desynchronization hypothesis
Directory of Open Access Journals (Sweden)
Full Text Available The traditional belief is that brain oscillations are important for human long-term memory, because they induce synchronized firing between cell assemblies which shapes synaptic plasticity. Therefore, most prior studies focused on the role of synchronization for episodic memory, as reflected in theta (~5 Hz and gamma (>40 Hz power increases. These studies, however, neglect the role that is played by neural desynchronization, which is usually reflected in power decreases in the alpha and beta frequency band (8-30 Hz. In this paper we present a first idea, derived from information theory that gives a mechanistic explanation of how neural desynchronization aids human memory encoding and retrieval. Thereby we will review current studies investigating the role of alpha and beta power decreases during long-term memory tasks and show that alpha and beta power decreases play an important and active role for human memory. Applying mathematical models of information theory, we demonstrate that neural desynchronization is positively related to the richness of information represented in the brain, thereby enabling encoding and retrieval of long-term memories. This information via desynchronization hypothesis makes several predictions, which can be tested in future experiments.
Making memories: the development of long-term visual knowledge in children with visual agnosia.
There are few reports about the effects of perinatal acquired brain lesions on the development of visual perception. These studies demonstrate nonseverely impaired visual-spatial abilities and preserved visual memory. Longitudinal data analyzing the effects of compromised perceptions on long-term visual knowledge in agnosics are limited to lesions having occurred in adulthood. The study of children with focal lesions of the visual pathways provides a unique opportunity to assess the development of visual memory when perceptual input is degraded. We assessed visual recognition and visual memory in three children with lesions to the visual cortex having occurred in early infancy. We then explored the time course of visual memory impairment in two of them at 2 ?years and 3.7 ?years from the initial assessment. All children exhibited apperceptive visual agnosia and visual memory impairment. We observed a longitudinal improvement of visual memory modulated by the structural properties of objects. Our findings indicate that processing of degraded perceptions from birth results in impoverished memories. The dynamic interaction between perception and memory during development might modulate the long-term construction of visual representations, resulting in less severe impairment. PMID:24319599
Metitieri, Tiziana; Barba, Carmen; Pellacani, Simona; Viggiano, Maria Pia; Guerrini, Renzo
Hippocampal long term memory: effect of the cholinergic system on local protein synthesis.
The present study was aimed at establishing a link between the cholinergic system and the pathway of mTOR and its downstream effector p70S6K, likely actors in long term memory encoding. We performed in vivo behavioral experiments using the step down inhibitory avoidance test (IA) in adult Wistar rats to evaluate memory formation under different conditions, and immunohistochemistry on hippocampal slices to evaluate the level and the time-course of mTOR and p70S6K activation. We also examined the effect of RAPA, inhibitor of mTORC1 formation, and of the acetylcholine (ACh) muscarinic receptor antagonist scopolamine (SCOP) or ACh nicotinic receptor antagonist mecamylamine (MECA) on short and long term memory formation and on the functionality of the mTOR pathway. Acquisition test was performed 30 min after i.c.v. injection of RAPA, a time sufficient for the drug to diffuse to CA1 pyramidal neurons, as demonstrated by MALDI-TOF-TOF imaging. Recall test was performed 1 h, 4 h or 24 h after acquisition. To confirm our results we performed in vitro experiments on live hippocampal slices: we evaluated whether stimulation of the cholinergic system with the cholinergic receptor agonist carbachol (CCh) activated the mTOR pathway and whether the administration of the above-mentioned antagonists together with CCh could revert this activation. We found that (1) mTOR and p70S6K activation in the hippocampus were involved in long term memory formation; (2) RAPA administration caused inhibition of mTOR activation at 1 h and 4 h and of p70S6K activation at 4 h, and long term memory impairment at 24 h after acquisition; (3) scopolamine treatment caused short but not long term memory impairment with an early increase of mTOR/p70S6K activation at 1 h followed by stabilization at longer times; (4) mecamylamine plus scopolamine treatment caused short term memory impairment at 1 h and 4 h and reduced the scopolamine-induced increase of mTOR/p70S6K activation at 1 h and 4 h; (5) mecamylamine plus scopolamine treatment did not impair long term memory formation; (6) in vitro treatment with carbachol activated mTOR and p70S6K and this effect was blocked by scopolamine and mecamylamine. Taken together our data reinforce the idea that distinct molecular mechanisms are at the basis of the two different forms of memory and are in accordance with data presented by other groups that there exist molecular mechanisms that underlie short term memory, others that underlie long term memories, but some mechanisms are involved in both. PMID:24076274
Lana, Daniele; Cerbai, Francesca; Di Russo, Jacopo; Boscaro, Francesca; Giannetti, Ambra; Petkova-Kirova, Polina; Pugliese, Anna Maria; Giovannini, Maria Grazia
Increased NR2A:NR2B ratio compresses long-term depression range and constrains long-term memory
Digital Repository Infrastructure Vision for European Research (DRIVER)
The NR2A:NR2B subunit ratio of the NMDA receptors is widely known to increase in the brain from postnatal development to sexual maturity and to aging, yet its impact on memory function remains speculative. We have generated forebrain-specific NR2A overexpression transgenic mice and show that these mice had normal basic behaviors and short-term memory, but exhibited broad long-term memory deficits as revealed by several behavioral paradigms. Surprisingly, increased NR2A expression did not affe...
Zhenzhong Cui; Ruiben Feng; Stephanie Jacobs; Yanhong Duan; Huimin Wang; Xiaohua Cao; Tsien, Joe Z.
Mechanism for long-term memory formation when synaptic strengthening is impaired
Digital Repository Infrastructure Vision for European Research (DRIVER)
Long-term memory (LTM) formation has been linked with functional strengthening of existing synapses and other processes including de novo synaptogenesis. However, it is unclear whether synaptogenesis can contribute to LTM formation. Here, using ?-calcium/calmodulin kinase II autophosphorylation-deficient (T286A) mutants, we demonstrate that when functional strengthening is severely impaired, contextual LTM formation is linked with training-induced PSD95 up-regulation followed by persistent g...
Statistical traces of long-term memories stored in strengths and patterns of synaptic connections
Digital Repository Infrastructure Vision for European Research (DRIVER)
Learning and long-term memory rely on plasticity of neural circuits. In adult cerebral cortex plasticity can result from potentiation and depression of synaptic strengths and structural reorganization of circuits through growth and retraction of dendritic spines. By analyzing 166 distributions of spine head volumes and spine lengths from mouse, rat, monkey, and human brains, we determine the �generalized cost� of dendritic spines. This cost universally depends on spine shape, i.e. the dep...
Stepanyants Armen; Escobar Gina
Tests of the protein-synthesis hypothesis of formation of long-term memory
Energy Technology Data Exchange (ETDEWEB)
A major hypothesis has been that synthesis of protein is required for formation of long-term memory. Results of many studies conducted during the past decade have supported this hypothesis, but different limitations have been suggested and competing interpretations have been offered. Several alternative hypotheses have also been proposed and data have been offered in favor of them. We will review some of the results both for and against the protein-synthesis hypothesis.
Rosenzweig, M.R.; Bennett, E.L.; Flood, J.F.
Extreme event return times in long-term memory processes near 1/f
Digital Repository Infrastructure Vision for European Research (DRIVER)
The distribution of extreme event return times and their correlations are analyzed in observed and simulated long-term memory (LTM) time series with 1/f power spectra. The analysis is based on tropical temperature and mixing ratio (specific humidity) time series from TOGA COARE with 1 min resolution and an approximate 1/f power spectrum. Extreme events are determined by Peak-Over-Threshold (POT) crossing. The Weibull distribution represents a reasonable fit to the return time di...
Blender, R.; Fraedrich, K.; Sienz, F.
Measuring capital market efficiency: Long-term memory, fractal dimension and approximate entropy
Digital Repository Infrastructure Vision for European Research (DRIVER)
We utilize long-term memory, fractal dimension and approximate entropy as input variables for the Efficiency Index [Kristoufek & Vosvrda (2013), Physica A 392]. This way, we are able to comment on stock market efficiency after controlling for different types of inefficiencies. Applying the methodology on 38 stock market indices across the world, we find that the most efficient markets are situated in the Eurozone (the Netherlands, France and Germany) and the least efficient ...
Kristoufek, Ladislav; Vosvrda, Miloslav
CNTRICS Imaging Biomarkers Final Task Selection: Long-Term Memory and Reinforcement Learning
Digital Repository Infrastructure Vision for European Research (DRIVER)
Functional imaging paradigms hold great promise as biomarkers for schizophrenia research as they can detect altered neural activity associated with the cognitive and emotional processing deficits that are so disabling to this patient population. In an attempt to identify the most promising functional imaging biomarkers for research on long-term memory (LTM), the Cognitive Neuroscience Treatment Research to Improve Cognition in Schizophrenia (CNTRICS) initiative selected �item encoding and r...
Ragland, John D.; Cohen, Neal J.; Cools, Roshan; Frank, Michael J.; Hannula, Deborah E.; Ranganath, Charan
Demonstration of long-term memory in the parasitic wasp Nasonia vitripennis
Digital Repository Infrastructure Vision for European Research (DRIVER)
We studied the formation of protein synthesis-dependent long-term memory (LTM) in the parasitic wasp Nasonia vitripennis Walker (Hymenoptera: Pteromalidae), a parasitoid of fly pupae. Female wasps were trained in one of five different training procedures in the presence of hosts and the odour cinnamon. Six days later the reaction of the wasps towards the odour was tested in a static four-chamber olfactometer. When wasps were trained by a single drilling experience we could not find any reacti...
Schurmann, D.; Sommer, C.; Schinko, A. P. B.; Greschista, M.; Smid, H. M.; Steidle, J. L. M.
Operant Conditioning in Lymnaea: Evidence for Intermediate- and Long-term Memory
Digital Repository Infrastructure Vision for European Research (DRIVER)
Aerial respiration of the pond snail, Lymnaea stagnalis, can be operantly conditioned; however, the parameters necessary to produce long-term (LTM) or intermediate term memory (ITM) have not previously been investigated. We conducted training using procedures that varied in the duration of the training session, the number of training sessions per day or the amount of time between subsequent training sessions (SI). We found that by varying the duration and frequency of the training session lea...
Lukowiak, Ken; Adatia, Nimet; Krygier, Darin; Syed, Naweed
Impairment of recognition memory and hippocampal long-term potentiation after acute exposure to clioquinol.
Clioquinol (CQ) was associated with cases of transient global amnesia and with the neurodegenerative syndrome subacute myelo-optico-neuropathy (SMON) in humans. However, CQ forms lipophilic chelates with cations and has the potential as a scientific and clinical tool used for selective modulation of histochemically reactive zinc pools. The relationship among transient lack of synaptic zinc release, hippocampal long-term potentiation (LTP) induction and cognitive memory is poorly understood. To evaluate the role of synaptic zinc release, in the present study, hippocampal LTP induction and cognitive behavior were examined in young rats after i.p. injection of CQ (30 mg/kg). Intracellular zinc detected by Timm's stain and extracellular (synaptic cleft) zinc detected by ZnAF-2 were significantly decreased in the hippocampus 6 h after CQ injection. The molecular layer of the dentate gyrus, in which perforant path-granule cell synapses exist, was most responsive to CQ injection. Dentate gyrus LTP was induced similarly to the control 2 h after CQ injection, while significantly attenuated 6-24 h after CQ injection. In the training trial of the object recognition memory 2 h after CQ injection, there was no significant difference in learning behavior between the control and CQ-treated rats. In the test trial, CQ-treated rats showed normal recognition memory 1 h after the training, whereas recognition memory deficit 24 h after the training unlike the control rats. These results indicate that acute exposure to CQ impairs long-term (24 h) memory in the hippocampus of young rats. The CQ-mediated attenuation of dentate gyrus LTP, which may be associated with the transient lack of zinc release from zincergic neurons, seems to be involved in the impairment of the long-term memory. PMID:20849933
Takeda, A; Takada, S; Ando, M; Itagaki, K; Tamano, H; Suzuki, M; Iwaki, H; Oku, N
Effects of event valence on long-term memory for two baseball championship games.
We investigated how event valence affected accuracy and vividness of long-term memory for two comparable public events. In 2008, 1,563 fans answered questions about objective details concerning two decisive baseball championship games between the Yankees (2003 winners) and the Red Sox (2004 winners). Both between- and within-groups analyses indicated that fans remembered the game their team won significantly more accurately than the game their team lost. Fans also reported more vividness and more rehearsal for the game their team won. We conclude that individuals rehearse positive events more than comparable negative events, and that this additional rehearsal increases both vividness and accuracy of memories about positive events. Our results differ from those of prior studies involving memories for negative events that may have been unavoidably rehearsed; such rehearsal may have kept those memories from fading. Long-term memory for an event is determined not only by the valence of the event, but also by experiences after the event. PMID:22006058
Breslin, Carolyn W; Safer, Martin A
Neurabin contributes to hippocampal long-term potentiation and contextual fear memory.
Neurabin is a scaffolding protein that interacts with actin and protein phosphatase-1. Highly enriched in the dendritic spine, neurabin is important for spine morphogenesis and synaptic formation. However, less is known about the role of neurabin in hippocampal plasticity and its possible effect on behavioral functions. Using neurabin knockout (KO) mice, here we studied the function of neurabin in hippocampal synaptic transmission, plasticity and behavioral memory. We demonstrated that neurabin KO mice showed a deficit in contextual fear memory but not auditory fear memory. Whole-cell patch clamp recordings in the hippocampal CA1 neurons showed that long-term potentiation (LTP) was significantly reduced, whereas long-term depression (LTD) was unaltered in neurabin KO mice. Moreover, increased AMPA receptor but not NMDA receptor-mediated synaptic transmission was found in neurabin KO mice, and is accompanied by decreased phosphorylation of GluR1 at the PKA site (Ser845) but no change at the CaMKII/PKC site (Ser831). Pre-conditioning with LTD induction rescued the following LTP in neurabin KO mice, suggesting the loss of LTP may be due to the saturated synaptic transmission. Our results indicate that neurabin regulates contextual fear memory and LTP in hippocampal CA1 pyramidal neurons. PMID:18183288
Wu, Long-Jun; Ren, Ming; Wang, Hansen; Kim, Susan S; Cao, Xiaoyan; Zhuo, Min
Verapamil enhances the impairing effects of stress on retrieval of long-term memory in rats
Directory of Open Access Journals (Sweden)
Full Text Available Introduction: This study investigated an interaction between acute restraint stress and verapamil, as a blocker of L-type voltage sensitive channels on retrieval of long-term memory. Materials and Methods: Young adult male rats were trained in one trial inhibitory avoidance task (1mA, 1.5s footshock. On retention test given 48 hr after training, the latency to re-enter dark compartment and time spent in light chamber of the apparatus were recorded. Thirty min before retention test, the rats were exposed to a 10 min of restraint stress in a Plexiglass with or without prior treatment of verapamil (5, 10, 20 mg/kg. Results: The results showed verapamil pretreatment enhanced the impairing effect of stress on memory retrieval. The applied stress increased circulating corticosterone levels as assessed immediately after the retention test, indicating that stress�induced impairment of memory retrieval is mediated, in part, by increased plasma levels of glucocorticoids. Verapamil did not affect on this response. Conclusion: These findings indicate that acute restraint stress impair retrieval of long-term memory, and provide evidence for the existence of an interaction between stress and L-type voltage calcium channels on this process.
A. Rashidy-Pour
Transgenic overexpression of the type I isoform of neuregulin 1 affects working memory and hippocampal oscillations but not long-term potentiation.
Neuregulin 1 (NRG1) is a growth factor involved in neurodevelopment and plasticity. It is a schizophrenia candidate gene, and hippocampal expression of the NRG1 type I isoform is increased in the disorder. We have studied transgenic mice overexpressing NRG1 type I (NRG1(tg-type I)) and their wild-type littermates and measured hippocampal electrophysiological and behavioral phenotypes. Young NRG1(tg-type I) mice showed normal memory performance, but in older NRG1(tg-type I) mice, hippocampus-dependent spatial working memory was selectively impaired. Hippocampal slice preparations from NRG1(tg-type I) mice exhibited a reduced frequency of carbachol-induced gamma oscillations and an increased tendency to epileptiform activity. Long-term potentiation in NRG1(tg-type I) mice was normal. The results provide evidence that NRG1 type I impacts on hippocampal function and circuitry. The effects are likely mediated via inhibitory interneurons and may be relevant to the involvement of NRG1 in schizophrenia. However, the findings, in concert with those from other genetic and pharmacological manipulations of NRG1, emphasize the complex and pleiotropic nature of the gene, even with regard to a single isoform. PMID:21878485
Deakin, Inga H; Nissen, Wiebke; Law, Amanda J; Lane, Tracy; Kanso, Riam; Schwab, Markus H; Nave, Klaus-Armin; Lamsa, Karri P; Paulsen, Ole; Bannerman, David M; Harrison, Paul J
Transgenic Overexpression of the Type I Isoform of Neuregulin 1 Affects Working Memory and Hippocampal Oscillations but not Long-term Potentiation
Neuregulin 1 (NRG1) is a growth factor involved in neurodevelopment and plasticity. It is a schizophrenia candidate gene, and hippocampal expression of the NRG1 type I isoform is increased in the disorder. We have studied transgenic mice overexpressing NRG1 type I (NRG1tg-type I) and their wild-type littermates and measured hippocampal electrophysiological and behavioral phenotypes. Young NRG1tg-type I mice showed normal memory performance, but in older NRG1tg-type I mice, hippocampus-dependent spatial working memory was selectively impaired. Hippocampal slice preparations from NRG1tg-type I mice exhibited a reduced frequency of carbachol-induced gamma oscillations and an increased tendency to epileptiform activity. Long-term potentiation in NRG1tg-type I mice was normal. The results provide evidence that NRG1 type I impacts on hippocampal function and circuitry. The effects are likely mediated via inhibitory interneurons and may be relevant to the involvement of NRG1 in schizophrenia. However, the findings, in concert with those from other genetic and pharmacological manipulations of NRG1, emphasize the complex and pleiotropic nature of the gene, even with regard to a single isoform.
Deakin, Inga H.; Nissen, Wiebke; Law, Amanda J.; Lane, Tracy; Kanso, Riam; Schwab, Markus H.; Nave, Klaus-Armin; Lamsa, Karri P.; Paulsen, Ole; Bannerman, David M.
Deficient long-term memory and long-lasting long-term potentiation in mice with a targeted deletion of neurotrophin-4 gene
Digital Repository Infrastructure Vision for European Research (DRIVER)
We examined the learning and memory of neurotrophin-4 (NT4)?/? mice by using fear conditioning. In both cue and context conditioning, we found significant deficits in the NT4 mutants at 2 and 24 h after training but not at 30 min. Hippocampal slices from the mutant mice showed normal basal synaptic transmission, short-term plasticity, and decremental long-term potentiation (LTP) at the Schaffer collateral-CA1 synapses. These findings, together with the normal short-term memory, suggest th...
Xie, Cui-wei; Sayah, David; Chen, Qi-sheng; Wei, Wei-zheng; Smith, Desmond; Liu, Xin
Fragile X mental retardation 1 and Filamin A interact genetically in Drosophila long-term memory
Directory of Open Access Journals (Sweden)
Full Text Available The last decade has witnessed the identification of single-gene defects associated with an impressive number of mental retardation syndromes. Fragile X syndrome, the most common cause of mental retardation for instance, results from disruption of the FMR1 gene. Similarly, Periventricular Nodular Heterotopia (PNH, which includes cerebral malformation, epilepsy and cognitive disabilities, derives from disruption of the Filamin A gene. While it remains unclear whether defects in common molecular pathways may underlie the cognitive dysfunction of these various syndromes, defects in cytoskeletal structure nonetheless appear to be common to several mental retardation syndromes. FMR1 is known to interact with Rac, profilin, PAK and Ras, which are associated with dendritic spine defects. In Drosophila, disruptions of the dFmr1 gene impair long-term memory, and the Filamin A homolog (cheerio was identified in a behavioral screen for long-term memory mutants. Thus, we investigated the possible interaction between cheerio and dFmr1 during long-term memory (LTM formation in Drosophila. We show that LTM specifically is defective in dFmr1/cheerio double heterozygotes, while it is normal in single heterozygotes for either dFmr1 or cheerio. In dFmr1 mutants, Filamin (Cheerio levels are lower than normal after spaced training. These observations support the notion that decreased actin cross-linking underlies the persistence of long and thin dendritic spines in Fragile X patients and animal models. More generally, our results represent the first demonstration of a genetic interaction between mental retardation genes in an in vivo model system of memory formation.
Extreme event return times in long-term memory processes near 1/f
Directory of Open Access Journals (Sweden)
Full Text Available The distribution of extreme event return times and their correlations are analyzed in observed and simulated long-term memory (LTM time series with 1/f power spectra. The analysis is based on tropical temperature and mixing ratio (specific humidity time series from TOGA COARE with 1 min resolution and an approximate 1/f power spectrum. Extreme events are determined by Peak-Over-Threshold (POT crossing. The Weibull distribution represents a reasonable fit to the return time distributions while the power-law predicted by the stretched exponential for 1/f deviates considerably. For a comparison and an analysis of the return time predictability, a very long simulated time series with an approximate 1/f spectrum is produced by a fractionally differenced (FD process. This simulated data confirms the Weibull distribution (a power law can be excluded. The return time sequences show distinctly weaker long-term correlations than the original time series (correlation exponent ??0.56.
F. Sienz
PKG-mediated MAPK signaling is necessary for long-term operant memory in Aplysia
Signaling pathways necessary for memory formation, such as the mitogen-activated protein kinase (MAPK) pathway, appear highly conserved across species and paradigms. Learning that food is inedible (LFI) represents a robust form of associative, operant learning that induces short- (STM) and long-term memory (LTM) in Aplysia. We investigated the role of MAPK signaling in LFI memory in vivo. Inhibition of MAPK activation in animals prior to training blocked STM and LTM. Discontinuing MAPK signaling immediately after training inhibited LTM with no impact on STM. Therefore, MAPK signaling appears necessary early in memory formation for STM and LTM, with prolonged MAPK activity required for LTM. We found that LFI training significantly increased phospho-MAPK levels in the buccal ganglia. Increased MAPK activation was apparent immediately after training with greater than basal levels persisting for 2 h. We examined the mechanisms underlying training-induced MAPK activation and found that PKG activity was necessary for the prolonged phase of MAPK activation, but not for the early MAPK phase required for STM. Furthermore, we found that neither the immediate nor the prolonged phase of MAPK activation was dependent upon nitric oxide (NO) signaling, although expression of memory was dependent on NO as previously reported. These studies emphasize the role of MAPK and PKG in negatively reinforced operant memory and demonstrate a role for PKG-dependent MAPK signaling in invertebrate associative memory.
Michel, Maximilian; Green, Charity L.; Eskin, Arnold; Lyons, Lisa C.
Ethanol Sensitivity and Tolerance in Long-Term Memory Mutants of Drosophila melanogaster
Background It has become increasingly clear that molecular and neural mechanisms underlying learning and memory and drug addiction are largely shared. To confirm and extend these findings, we analyzed ethanol-responsive behaviors of a collection of Drosophila long-term memory mutants. Methods For each mutant, sensitivity to the acute uncoordinating effects of ethanol was quantified using the inebriometer. Additionally, 2 distinct forms of ethanol tolerance were measured: rapid tolerance, which develops in response to a single brief exposure to a high concentration of ethanol vapor; and chronic tolerance, which develops following a sustained low-level exposure. Results Several mutants were identified with altered sensitivity, rapid or chronic tolerance, while a number of mutants exhibited multiple defects. Conclusions The corresponding genes in these mutants represent areas of potential overlap between learning and memory and behavioral responses to alcohol. These genes also define components shared between different ethanol behavioral responses.
Berger, Karen H.; Kong, Eric C.; Dubnau, Josh; Tully, Tim; Moore, Monica S.; Heberlein, Ulrike
Sleep Improves Memory: The Effect of Sleep on Long Term Memory in Early Adolescence
Digital Repository Infrastructure Vision for European Research (DRIVER)
Sleep plays an important role in the consolidation of memory. This has been most clearly shown in adults for procedural memory (i.e. skills and procedures) and declarative memory (e.g. recall of facts). The effects of sleep and memory are relatively unstudied in adolescents. Declarative memory is important in school performance and consequent social functioning in adolescents. This is the first study to specifically examine the effects of normal sleep on auditory declarative memory in an earl...
Potkin, Katya Trudeau; Bunney, William E.
Strategic search from long-term memory: An examination of semantic and autobiographical recall.
Searching long-term memory is theoretically driven by both directed (search strategies) and random components. In the current study we conducted four experiments evaluating strategic search in semantic and autobiographical memory. Participants were required to generate either exemplars from the category of animals or the names of their friends for several minutes. Self-reported strategies suggested that participants typically relied on visualization strategies for both tasks and were less likely to rely on ordered strategies (e.g., alphabetic search). When participants were instructed to use particular strategies, the visualization strategy resulted in the highest levels of performance and the most efficient search, whereas ordered strategies resulted in the lowest levels of performance and fairly inefficient search. These results are consistent with the notion that retrieval from long-term memory is driven, in part, by search strategies employed by the individual, and that one particularly efficient strategy is to visualize various situational contexts that one has experienced in the past in order to constrain the search and generate the desired information. PMID:23885826
Unsworth, Nash; Brewer, Gene A; Spillers, Gregory J
Impaired fear memory specificity associated with deficient endocannabinoid-dependent long-term plasticity.
In addition to its central role in learning and memory, N-methyl D-aspartate receptor (NMDAR)-dependent signaling regulates central glutamatergic synapse maturation and has been implicated in schizophrenia. We have transiently induced NMDAR hypofunction in infant mice during postnatal days 7-11, followed by testing fear memory specificity and presynaptic plasticity in the prefrontal cortex (PFC) in adult mice. We show that transient NMDAR hypofunction during early brain development, coinciding with the maturation of cortical plasticity results in a loss of an endocannabinoid (eCB)-mediated form of long-term depression (eCB-LTD) at adult central glutamatergic synapses, while another form of presynaptic long-term depression mediated by the metabotropic glutamate receptor 2/3 (mGluR2/3-LTD) remains intact. Mice with this selective impairment of presynaptic plasticity also showed deficits in fear memory specificity. The observed deficit in cortical presynaptic plasticity may represent a neural maladaptation contributing to network instability and abnormal cognitive functioning. PMID:24457285
Lovelace, Jonathan W; Vieira, Philip A; Corches, Alex; Mackie, Ken; Korzus, Edward
The estimation of long-term memory characteristics in MEA neuronal culture recordings.
The nonlinear analysis of multichannel MEA recordings from neuronal networks is becoming a central topic in Neuroengineering. Up-to-date these kind of analyses required complex ad hoc methods. In this paper we introduce a new approach that allows the analysis of the whole-neuronal-network-activity with well-established nonlinear signal processing methods. In particular, we show here the estimation of long-term-memory behaviors through the Periodogram method in the bursting activity of cortical neuron cultures during development. Moreover, we show how this method is able to highlight structural activity changes of the network. PMID:19162831
Esposti, Federico; Signorini, Maria Gabriella
The evidence for hippocampal long-term potentiation as a basis of memory for simple tasks
Directory of Open Access Journals (Sweden)
Full Text Available Long-term potentiation (LTP is the enhancement of postsynaptic responses for hours, days or weeks following the brief repetitive afferent stimulation of presynaptic afferents. It has been proposed many times over the last 30 years to be the basis of long-term memory. Several recent findings finally supported this hypothesis: a memory formation of one-trial avoidance learning depends on a series of molecular steps in the CA1 region of the hippocampus almost identical to those of LTP in the same region; bhippocampal LTP in this region accompanies memory formation of that task and of another similar task. However, CA1 LTP and the accompanying memory processes can be dissociated, and in addition plastic events in several other brain regions(amygdala, entorhinal cortex, parietal cortex are also necessary for memory formation of the one-trial task, and perhaps of many others.A potencia��o de longa dura��o (LTP � o aumento de respostas p�s-sin�pticas durante horas, dias ou semanas ap�s a breve estimula��o repetitiva de aferentes pre-sin�pticos. Foi proposto durante 30 anos ser a base da mem�ria de longa dura��o. V�rios achados recentes finalmente apoiaram esta hip�tese: a a forma��o da mem�ria de esquiva inibit�ria adquirida numa sess�o depende de uma cadeia de processos moleculares na regi�o CA1 do hipocampo quase id�ntica � da LTP nessa mesma regi�o; b LTP hipocampal nessa regi�o acompanha a forma��o da mem�r�a dessa tarefa e de outra semelhante. No entanto, a LTP de CA1 e os processos de mem�ria podem ser dissociados e, fora disso, processos pl�sticos em outras regi�es cerebrais (am�gdala, c�rtex entorrinal, c�rtex parietal tamb�m s�o necess�rios para a forma��o da mem�ria da tarefa de uma sess�o e talvez de muitas outras.
Iv�n Izquierdo
The evidence for hippocampal long-term potentiation as a basis of memory for simple tasks
Scientific Electronic Library Online (English)
Full Text Available SciELO Brazil | Language: English Abstract in portuguese A potencia��o de longa dura��o (LTP) � o aumento de respostas p�s-sin�pticas durante horas, dias ou semanas ap�s a breve estimula��o repetitiva de aferentes pre-sin�pticos. Foi proposto durante 30 anos ser a base da mem�ria de longa dura��o. V�rios achados recentes finalmente apoiaram esta hip�tese: [...] a) a forma��o da mem�ria de esquiva inibit�ria adquirida numa sess�o depende de uma cadeia de processos moleculares na regi�o CA1 do hipocampo quase id�ntica � da LTP nessa mesma regi�o; b) LTP hipocampal nessa regi�o acompanha a forma��o da mem�r�a dessa tarefa e de outra semelhante. No entanto, a LTP de CA1 e os processos de mem�ria podem ser dissociados e, fora disso, processos pl�sticos em outras regi�es cerebrais (am�gdala, c�rtex entorrinal, c�rtex parietal) tamb�m s�o necess�rios para a forma��o da mem�ria da tarefa de uma sess�o e talvez de muitas outras. Abstract in english Long-term potentiation (LTP) is the enhancement of postsynaptic responses for hours, days or weeks following the brief repetitive afferent stimulation of presynaptic afferents. It has been proposed many times over the last 30 years to be the basis of long-term memory. Several recent findings finally [...] supported this hypothesis: a) memory formation of one-trial avoidance learning depends on a series of molecular steps in the CA1 region of the hippocampus almost identical to those of LTP in the same region; b)hippocampal LTP in this region accompanies memory formation of that task and of another similar task. However, CA1 LTP and the accompanying memory processes can be dissociated, and in addition plastic events in several other brain regions(amygdala, entorhinal cortex, parietal cortex) are also necessary for memory formation of the one-trial task, and perhaps of many others.
Iv�n, Izquierdo; Mart�n, Cammarota; Weber C. Da, Silva; Lia R.M., Bevilaqua; Janine I., Rossato; Juliana S., Bonini; Pamela, Mello; Fernando, Benetti; Jaderson C., Costa; Jorge H., Medina.
Exchange Protein Activated by cAMP Enhances Long-Term Memory Formation Independent of Protein Kinase A
It is well established that cAMP signaling within neurons plays a major role in the formation of long-term memories--signaling thought to proceed through protein kinase A (PKA). However, here we show that exchange protein activated by cAMP (Epac) is able to enhance the formation of long-term memory in the hippocampus and appears to do so�
Ma, Nan; Abel, Ted; Hernandez, Pepe J.
From Drosophila development to adult: clues to Notch function in long-term memory
Directory of Open Access Journals (Sweden)
Full Text Available Notch is a cell surface receptor that is well known to mediate inter-cellular communication during animal development. Data in the field indicate that it is also involved in the formation of long-term memory (LTM in the fully developed adults and in memory loss upon neurodegeneration. Our studies in the model organism Drosophila reveal that a non-canonical Notch-Protein Kinase C (PKC activity that plays critical roles in embryonic development also regulates Cyclic-AMP Response Element Binding protein (CREB during LTM formation in adults. Here we present a perspective on how the various known features of Notch function relate to LTM formation and how they might interface with elements of Wingless/Wnt signaling in this process.
Valence and the development of immediate and long-term false memory illusions.
Across five experiments we examined the role of valence in children's and adults' true and false memories. Using the Deese/Roediger-McDermott paradigm and either neutral or negative-emotional lists, both adults' (Experiment 1) and children's (Experiment 2) true recall and recognition was better for neutral than negative items, and although false recall was also higher for neutral items, false recognition was higher for negative items. The last three experiments examined adults' (Experiment 3) and children's (Experiments 4 and 5) 1-week long-term recognition of neutral and negative-emotional information. The results replicated the immediate recall and recognition findings from the first two experiments. More important, these experiments showed that although true recognition decreased over the 1-week interval, false recognition of neutral items remained unchanged whereas false recognition of negative-emotional items increased. These findings are discussed in terms of theories of emotion and memory as well as their forensic implications. PMID:20391177
Howe, Mark L; Candel, Ingrid; Otgaar, Henry; Malone, Catherine; Wimmer, Marina C
Role of neurotransmitters and protein synthesis in short- and long-term memory
Energy Technology Data Exchange (ETDEWEB)
Anisomycin is an effective inhibitor of cerebral protein synthesis in mice and is also an effective amnestic agent for both passive and active behavioral tasks. From use of anisomycin in combination with a variety of stimulant and depressant drugs, it was concluded that the level of arousal following acquisition plays an important role in determining the duration and the rate of the biosynthetic phase of memory formation. While we have interpreted the experiments with anisomycin as evidence for an essential role of protein in memory storage, others have suggested that side effects of inhibitors of protein synthesis on catecholamine metabolism are the main cause of amnesia. Several experiments were therefore done to compare the effects of anisomycin and catecholamine inhibitors on memory. It was concluded that anisomycin's principal amnestic mechanism does not involve inhibition of the catecholamine system. The results strengthen the conclusion that protein synthesis is an essential component for long-term memory trace formation. Also, it is suggested that proteins synthesized in the neuronal cell body are used, in conjunction with other molecules, to produce permanent and semi-permanent anatomical changes.
Bennett, E.L.; Rosenzweig, M.R.; Flood, J.F.
Unforgettable film music: The role of emotion in episodic long-term memory for music
Directory of Open Access Journals (Sweden)
Full Text Available Abstract Background Specific pieces of music can elicit strong emotions in listeners and, possibly in connection with these emotions, can be remembered even years later. However, episodic memory for emotional music compared with less emotional music has not yet been examined. We investigated whether emotional music is remembered better than less emotional music. Also, we examined the influence of musical structure on memory performance. Results Recognition of 40 musical excerpts was investigated as a function of arousal, valence, and emotional intensity ratings of the music. In the first session the participants judged valence and arousal of the musical pieces. One week later, participants listened to the 40 old and 40 new musical excerpts randomly interspersed and were asked to make an old/new decision as well as to indicate arousal and valence of the pieces. Musical pieces that were rated as very positive were recognized significantly better. Conclusion Musical excerpts rated as very positive are remembered better. Valence seems to be an important modulator of episodic long-term memory for music. Evidently, strong emotions related to the musical experience facilitate memory formation and retrieval.
Altenm�ller Eckart O
Delayed emergence of effects of memory-enhancing drugs: implications for the dynamics of long-term memory.
Many theories of memory postulate that processing of information outlasts the learning situation and involves several different physiological substrates. If such physiologically distinct mechanisms or stages of memory do in fact exist, they should be differentially affected by particular experimental manipulations. Accordingly, a selective improvement of the processes underlying short-term memory should be detectable only while the information is encoded in the short-term mode, and a selective influence on long-term memory should be detectable only from the moment when memory is based on the long-term trace. Our comparative study of the time course of the effects of the cholinergic agonist arecoline, the gamma-aminobutyric acid type B receptor antagonist CGP 36742, the angiotensin-converting enzyme inhibitor captopril, and the nootropic oxiracetam, four substances with completely different primary sites of action, show that the memory-enhancing effects consistently come into evidence no sooner than 16-24 h after the learning trial. On the one hand, this finding suggests that all these substances act by way of the same type of mechanism; on the other hand, it demonstrates that the substrate modulated by the compounds forms the basis of memory only after 16-24 h. From the observation that animals also show clear signs of retention during the first 16 h--i.e., before the effects of the substances are measurable--it can be inferred that retention during this time is mediated by other mechanisms that are not influenced by any of the substances. Images
Mondadori, C; Hengerer, B; Ducret, T; Borkowski, J
Cholinergic systems and long-term potentiation in memory-impaired apolipoprotein E-deficient mice.
Impairments in cholinergic neurotransmitter systems of the basal forebrain are a hallmark of Alzheimer's disease pathophysiology. The presence of the epsilon4 allele of apolipoprotein E was recently implicated as a major risk factor in both familial and sporadic Alzheimer's disease. The present study examined the integrity of cholinergic and non-cholinergic systems in apolipoprotein E-deficient, memory-impaired mice. Choline acetyltransferase activity, hippocampal acetylcholine release, nicotinic and muscarinic (M1 and M2) receptor binding sites and acetylcholinesterase cell or terminal density showed no signs of alteration in either three-month or 9.5-month-old apolipoprotein E-deficient mice compared to controls. In contrast, long-term potentiation was found to be markedly reduced in these mice, but increases in the strength of stimulation induced the same level of long-term potentiation as that observed in controls. These alterations did not appear to be the consequence of modifications in the binding properties of glutamatergic receptors (N-methyl-D-aspartate and [RS]-alpha-amino-3-hydroxy-5-methylisoxazole propionic acid) but from defective regulation of the (RS)-alpha-amino-3-hydroxy-5-methylisoxazole propionic acid receptor by phospholipase A2 activity. These results support the notion that apolipoprotein E plays a fundamental role in neuronal plasticity, which could in turn affect cognitive performance through imbalances in extra- and intracellular lipid homeostasis. PMID:10426483
Krzywkowski, P; Ghribi, O; Gagn�, J; Chabot, C; Kar, S; Rochford, J; Massicotte, G; Poirier, J
Long-Term Memory Deficits in Pavlovian Fear Conditioning in Ca2+/Calmodulin Kinase Kinase ?-Deficient Mice?
Digital Repository Infrastructure Vision for European Research (DRIVER)
Signaling by the Ca2+/calmodulin kinase (CaMK) cascade has been implicated in neuronal gene transcription, synaptic plasticity, and long-term memory consolidation. The CaM kinase kinase ? (CaMKK?) isoform is an upstream component of the CaMK cascade whose function in different behavioral and learning and memory paradigms was analyzed by targeted gene disruption in mice. CaMKK? mutants exhibited normal long-term spatial memory formation and cued fear conditioning but showed deficits in cont...
Blaeser, Frank; Sanders, Matthew J.; Truong, Nga; Ko, Shanelle; Wu, Long Jun; Wozniak, David F.; Fanselow, Michael S.; Zhuo, Min; Chatila, Talal A.
Long-term memory in experiments and numerical simulations of hydrodynamic and magnetohydrodynamic turbulence
We analyze time series stemming from experiments and direct numerical simulations of hydrodynamic and magnetohydrodynamic turbulence. Simulations are done in periodic boxes, but with a volumetric forcing chosen to mimic the geometry of the flow in the experiments, the von K�rm�n swirling flow between two counterrotating impellers. Parameters in the simulations are chosen to (within computational limitations) allow comparisons between the experiments and the numerical results. Conducting fluids are considered in all cases. Two different configurations are considered: a case with a weak externally imposed magnetic field and a case with self-sustained magnetic fields. Evidence of long-term memory and 1/f noise is observed in experiments and simulations, in the case with weak magnetic field associated with the hydrodynamic behavior of the shear layer in the von K�rm�n flow, and in the dynamo case associated with slow magnetohydrodynamic behavior of the large-scale magnetic field.
Mininni, P.; Dmitruk, P.; Odier, P.; Pinton, J.-F.; Plihon, N.; Verhille, G.; Volk, R.; Bourgoin, M.
Behavioral, Cellular, and Molecular Analysis of Memory in Aplysia II: Long-Term Facilitation.
Long-term facilitation (LTF) of Aplysia tail sensory neuron-motor neuron (SN-MN) synapses provides a synaptic correlate of memory for long-term behavioral sensitization of the tail-siphon withdrawal reflex. LTF can be induced by repeated exposures of serotonin (5HT) in the isolated pleural-pedal ganglion preparation. In addition, we have shown previously (Sherff and Carew, 1999) that LTF can also be induced by coincident 5HT exposure comprised of a single 25-min exposure of 5HT at the SN cell body and a 5 min pulse of 5HT at the SN-MN synapses. If synaptic 5HT is applied either 15 min before or after somatic 5HT, LTF is significantly reduced or is not induced at all. These results show that two anatomically remote cellular compartments can functionally interact within a surprisingly short time period. In this chapter, we discuss some of the mechanistic implications of this temporal constraint. We also find that coincident LTF and LTF induced by repeated pulses of 5HT differ (1) in whether they induce another temporal phase of facilitation (intermediate-term facilitation, ITF, expressed up to 1.5 hr after 5HT), and (2) in their requirements for protein synthesis. The results described both in this paper and in the preceding companion paper show that there are multiple forms of both ITF and LTF that differ in their induction and expression requirements, and at least in some instances, the different temporal phases of facilitation, and perhaps comparable phases of memory, can be induced independently of each other. PMID:21708770
Sherff, Carolyn M; Carew, Thomas J
Long-term potentiation in bone � a role for glutamate in strain-induced cellular memory?
Directory of Open Access Journals (Sweden)
Full Text Available Abstract Background The adaptive response of bone cells to mechanical strain is a primary determinant of skeletal architecture and bone mass. In vivo mechanical loading induces new bone formation and increases bone mineral density whereas disuse, immobilisation and weightlessness induce bone loss. The potency of mechanical strain is such that a single brief period of loading at physiological strain magnitude is able to induce a long-lasting osteogenic response that lasts for days. Although the process of mechanotransduction in bone is incompletely understood, observations that responses to mechanical strain outlast the duration of stimulation necessitate the existence of a form of cellular memory through which transient strain episodes are recorded, interpreted and remembered by bone cells. Recent evidence supports the existence of a complex multicellular glutamate-signalling network in bone that shares functional similarities to glutamatergic neurotransmission in the central nervous system. In neurones, these signalling molecules coordinate synaptic communication required to support learning and memory formation, through a complex process of long-term potentiation. Presentation of the hypothesis We hypothesise that osteoblasts use a cellular mechanism similar or identical to neuronal long-term potentiation in the central nervous system to mediate long-lasting changes in osteogenesis following brief periods of mechanical strain. Testing the hypothesis N-methyl-D-aspartate (NMDA receptor antagonism should inhibit the saturating response of mechanical strain and reduce the enhanced osteogenicity of segregated loading to that of an equivalent period of uninterrupted loading. Changes in ?-amino-3-hydroxy-5-methyl-isoxazole propionate (AMPA receptor expression, localisation and electrophysiological responses should be induced by mechanical strain and inhibited by modulators of neuronal long-term potentiation. Implications of the hypothesis If true, this hypothesis would provide a mechanism through which the skeleton could be pharmacologically primed to enhance or retrieve the normal osteogenic response to exercise. This would form a basis through which novel therapies could be developed to target osteoporosis and other prevalent bone disorders associated with low bone mass.
Genever Paul G
Mechanisms of translation control underlying long-lasting synaptic plasticity and the consolidation of long-term memory.
The complexity of memory formation and its persistence is a phenomenon that has been studied intensely for centuries. Memory exists in many forms and is stored in various brain regions. Generally speaking, memories are reorganized into broadly distributed cortical networks over time through systems level consolidation. At the cellular level, storage of information is believed to initially occur via altered synaptic strength by processes such as long-term potentiation. New protein synthesis is required for long-lasting synaptic plasticity as well as for the formation of long-term memory. The mammalian target of rapamycin complex 1 (mTORC1) is a critical regulator of cap-dependent protein synthesis and is required for numerous forms of long-lasting synaptic plasticity and long-term memory. As such, the study of mTORC1 and protein factors that control translation initiation and elongation has enhanced our understanding of how the process of protein synthesis is regulated during memory formation. Herein we discuss the molecular mechanisms that regulate protein synthesis as well as pharmacological and genetic manipulations that demonstrate the requirement for proper translational control in long-lasting synaptic plasticity and long-term memory formation. PMID:24484700
Santini, Emanuela; Huynh, Thu N; Klann, Eric
Reexamining the Relationship between Working Memory and Comprehension: The Role of Available Long-Term Memory
Two individual differences studies tested relationships between listening comprehension and two conceptualizations of working memory (WM) capacity. Recently, some theorists have stressed that the empirically indicated limits of rehearsal-based WM storage components are inconsistent with the amounts of information needed to accomplish complex�
Was, Christopher A.; Woltz, Dan J.
Evidence for Human Fronto-Central Gamma Activity during Long-Term Memory Encoding of Word Sequences
Digital Repository Infrastructure Vision for European Research (DRIVER)
Although human gamma activity (30�80 Hz) associated with visual processing is often reported, it is not clear to what extend gamma activity can be reliably detected non-invasively from frontal areas during complex cognitive tasks such as long term memory (LTM) formation. We conducted a memory experiment composed of 35 blocks each having three parts: LTM encoding, working memory (WM) maintenance and LTM retrieval. In the LTM encoding and WM maintenance parts, participants had to respectively...
Meeuwissen, Esther Berendina; Takashima, Atsuko; Ferna?ndez, Guille?n; Jensen, Ole
Word-frequency effects in long-term semantic priming and false memory.
Several studies have used the lexical decision task (LDT) with the Deese-Roediger-McDermott (DRM) false-memory paradigm to investigate whether long-term semantic priming (LTSP) occurs following presentation of lists of items (e.g., bed, dream, snore) for related non-presented lure words (e.g., sleep). However, results have been mixed, with some studies observing priming, whilst others have not. The present study had four goals: (i) to investigate the existence of LTSP in the LDT; (ii) to investigate effects of LTSP on standard effects of word frequency on LDT performance; (iii) to investigate the effect, if any, of word frequency on true and false recall; and (iv) to compare LDT performance with performance on a subsequent free-recall task. The findings showed (i) a significant effect of LTSP on LDT performance; (ii) no effect of LTSP on standard effects of word frequency on LDT performance; (iii) no effect of word frequency on either true or false free recall; and (iv) a significant relationship between LDT and free-recall performance. Implications of these findings for understanding LTSP and false memories are discussed. PMID:21752006
Sherman, Susan M; Jordan, Timothy R
Synthetic amyloid-beta oligomers impair long-term memory independently of cellular prion protein.
Inability to form new memories is an early clinical sign of Alzheimer's disease (AD). There is ample evidence that the amyloid-beta (Abeta) peptide plays a key role in the pathogenesis of this disorder. Soluble, bio-derived oligomers of Abeta are proposed as the key mediators of synaptic and cognitive dysfunction, but more tractable models of Abeta-mediated cognitive impairment are needed. Here we report that, in mice, acute intracerebroventricular injections of synthetic Abeta(1-42) oligomers impaired consolidation of the long-term recognition memory, whereas mature Abeta(1-42) fibrils and freshly dissolved peptide did not. The deficit induced by oligomers was reversible and was prevented by an anti-Abeta antibody. It has been suggested that the cellular prion protein (PrP(C)) mediates the impairment of synaptic plasticity induced by Abeta. We confirmed that Abeta(1-42) oligomers interact with PrP(C), with nanomolar affinity. However, PrP-expressing and PrP knock-out mice were equally susceptible to this impairment. These data suggest that Abeta(1-42) oligomers are responsible for cognitive impairment in AD and that PrP(C) is not required. PMID:20133875
Balducci, Claudia; Beeg, Marten; Stravalaci, Matteo; Bastone, Antonio; Sclip, Alessandra; Biasini, Emiliano; Tapella, Laura; Colombo, Laura; Manzoni, Claudia; Borsello, Tiziana; Chiesa, Roberto; Gobbi, Marco; Salmona, Mario; Forloni, Gianluigi
Synthetic amyloid-? oligomers impair long-term memory independently of cellular prion protein
Inability to form new memories is an early clinical sign of Alzheimer�s disease (AD). There is ample evidence that the amyloid-? (A?) peptide plays a key role in the pathogenesis of this disorder. Soluble, bio-derived oligomers of A? are proposed as the key mediators of synaptic and cognitive dysfunction, but more tractable models of A??mediated cognitive impairment are needed. Here we report that, in mice, acute intracerebroventricular injections of synthetic A?1�42 oligomers impaired consolidation of the long-term recognition memory, whereas mature A?1�42 fibrils and freshly dissolved peptide did not. The deficit induced by oligomers was reversible and was prevented by an anti-A? antibody. It has been suggested that the cellular prion protein (PrPC) mediates the impairment of synaptic plasticity induced by A?. We confirmed that A?1�42 oligomers interact with PrPC, with nanomolar affinity. However, PrP-expressing and PrP knock-out mice were equally susceptible to this impairment. These data suggest that A?1�42 oligomers are responsible for cognitive impairment in AD and that PrPC is not required.
Balducci, Claudia; Beeg, Marten; Stravalaci, Matteo; Bastone, Antonio; Sclip, Alessandra; Biasini, Emiliano; Tapella, Laura; Colombo, Laura; Manzoni, Claudia; Borsello, Tiziana; Chiesa, Roberto; Gobbi, Marco; Salmona, Mario; Forloni, Gianluigi
Identification of individual neurons reflecting short- and long-term visual memory in an arthropodo.
Ideally, learning-related changes should be investigated while they occur in vivo, but physical accessibility and stability limit intracellular studies. Experiments with insects and crabs demonstrate their remarkable capacity to learn and memorize visual features. However, the location and physiology of individual neurons underlying these processes is unknown. A recently developed crab preparation allows stable intracellular recordings from the optic ganglia to be performed in the intact animal during learning. In the crab Chasmagnathus, a visual danger stimulus (VDS) elicits animal escape, which declines after a few stimulus presentations. The long-lasting retention of this decrement is mediated by an association between contextual cues of the training site and the VDS, therefore, called context-signal memory (CSM). CSM is achieved only by spaced training. Massed training, on the contrary, produces a decline of the escape response that is short lasting and, because it is context independent, is called signal memory (SM). Here, we show that movement detector neurons (MDNs) from the lobula (third optic ganglion) of the crab modify their response to the VDS during visual learning. These modifications strikingly correlate with the rate of acquisition and with the duration of retention of both CSM and SM. Long-term CSM is detectable from the response of the neuron 1 d after training. In contrast to MDNs, identified neurons from the medulla (second optic ganglion) show no changes. Our results indicate that visual memory in the crab, and possibly other arthropods, including insects, is accounted for by functional changes occurring in neurons originating in the optic lobes. PMID:13679423
Tomsic, Daniel; Ber�n de Astrada, Mart�n; Sztarker, Julieta
Different circuit and monoamine mechanisms consolidate long-term memory in aversive and reward classical conditioning.
There has been considerable recent interest in comparing the circuit and monoamine-based mechanisms of aversive and reward-associative conditioning in a number of vertebrate and invertebrate model systems. The mollusc Lymnaea stagnalis provides a unique opportunity to explore changes in the neural and chemical pathways underlying these two different types of conditioning as its feeding circuitry has been thoroughly characterised. Animals can learn after a single trial to associate the same CS (amyl acetate) either with a punishment (quinine) or reward (sucrose), showing either a reduced or an elevated feeding response, respectively, to the CS. We previously showed that reward conditioning strengthened the direct excitatory pathway from the lips to the feeding central pattern generator in the buccal ganglia through the activation of feeding interneurons in the cerebral ganglia. Now we demonstrate that aversive conditioning enhances the strength of a different inhibitory pathway that suppresses feeding but has no effect on the excitatory pathway. Here we show that consolidation of long-term memory (LTM) in reward conditioning depends on dopamine but not octopamine. In contrast, aversive LTM depends on octopamine but not dopamine. Octopamine is the invertebrate equivalent of noradrenalin, so these results on the monoamine dependence of reward and aversive conditioning in Lymnaea resemble, at the transmitter receptor level, those in mammals but are the opposite of those in another invertebrate group, the insects. PMID:21070389
Kemenes, Ildik�; O'Shea, Michael; Benjamin, Paul R
CNTRICS Imaging Biomarkers Final Task Selection: Long-Term Memory and Reinforcement Learning
Functional imaging paradigms hold great promise as biomarkers for schizophrenia research as they can detect altered neural activity associated with the cognitive and emotional processing deficits that are so disabling to this patient population. In an attempt to identify the most promising functional imaging biomarkers for research on long-term memory (LTM), the Cognitive Neuroscience Treatment Research to Improve Cognition in Schizophrenia (CNTRICS) initiative selected �item encoding and retrieval,� �relational encoding and retrieval,� and �reinforcement learning� as key LTM constructs to guide the nomination process. This manuscript reports on the outcome of the third CNTRICS biomarkers meeting in which nominated paradigms in each of these domains were discussed by a review panel to arrive at a consensus on which of the nominated paradigms could be recommended for immediate translational development. After briefly describing this decision process, information is presented from the nominating authors describing the 4 functional imaging paradigms that were selected for immediate development. In addition to describing the tasks, information is provided on cognitive and neural construct validity, sensitivity to behavioral or pharmacological manipulations, availability of animal models, psychometric characteristics, effects of schizophrenia, and avenues for future development.
Ragland, John D.; Cohen, Neal J.; Cools, Roshan; Frank, Michael J.; Hannula, Deborah E.; Ranganath, Charan
Long-term memory: disruption by inhibitors of protein synthesis and cytoplasmic flow
Energy Technology Data Exchange (ETDEWEB)
Colchicine (60 ..mu..g/kg), an inhibitor of axoplasmic transport, administered subcutaneously to mice has no detectable effect on retention when given shortly after active avoidance training, nor did a pertaining injection of anisomycin (ANI) have an amnesic effect. However, when ANI was administered shortly prior to training and colchicine was administered after training, retention performance was impaired. The amnesic effect was dependent on the time at which colchicine was administered. The amnesic effect was also obtained when ANI was combined with either vinblastine (6 ..mu..g/kg) or podophyllotoxin (3 ..mu..g/kg), drugs that inhibit axoplasmic transport. Intracerebral injections of colchicine (60 ng to 60 pg) caused amnesia in subjects pretreated with ANI, but not in subjects pretreated with saline. Lumicolchicine, an isomer of colchicine, which has similar central nervous system effects but has a low binding affinity for microtubule protein, did not impair retention in ANI pretreated mice. It is suggested that axonal transport of recently synthesized protein is required for long-term memory storage.
Flood, J.F. (Univ. of Califorina, Los Angeles); Landry, D.W.; Bennett, E.L.; Jarvik, M.E.
Coherent nonlinear interference effect for devices of long-term memory with femtosecond pulses
Computer simulation of the response (polarization) of three-level systems (for example, of quantum dots) with the common upper level (the ?-scheme) was carried out for devices of long-term memory with femtosecond driving and signal pulses. For producing an efficient response, the pulse area should be on the order of ?. Under the action of the first driving pulse on the 1-2 transition and the simultaneous action of the probe pulse on the 3-2 transition, a long-lived polarization with the lifetime dependent on the lifetimes of the lower (1 and 3) levels appears owing to the nonlinear interference effect. Under the action of the second driving pulse, a signal pulse appears on the 3-2 transition, whose amplitude is proportional to the amplitude of the input probe pulse and exponentially decreases with the delay time between the first and the second driving pulses. The set of equations for the density matrix was solved numerically in the semiclassical approximation and in the rotating wave approximation. The temporal evolution of the nondiagonal matrix elements reflects the temporal evolution of the nonlinear polarization. The polarization spectrum is found by the Fourier transform of the time dependence of the nondiagonal elements. The polarization spectrum (the power spectrum) possesses an interference structure with a fringe period governed by the delay time between the first and the second driving pulses. The inverse Fourier transform reconstructs the temporal shape of the pulses.
Pul'Kin, S. A.; Savel'Eva, M. Yu.; Fradkin, �. E.; Uvarova, S. V.
Fan-Shaped Body Neurons Are Involved in "Period"-Dependent Regulation of Long-Term Courtship Memory in "Drosophila"
In addition to its established function in the regulation of circadian rhythms, the "Drosophila" gene "period" ("per") also plays an important role in processing long-term memory (LTM). Here, we used courtship conditioning as a learning paradigm and revealed that (1) overexpression and knocking down of "per" in subsets of brain neurons enhance and�
Sakai, Takaomi; Inami, Show; Sato, Shoma; Kitamoto, Toshihiro
Hippocampal CA1 Kindling but Not Long-Term Potentiation Disrupts Spatial Memory Performance
Long-term synaptic enhancement in the hippocampus has been suggested to cause deficits in spatial performance. Synaptic enhancement has been reported after hippocampal kindling that induced repeated electrographic seizures or afterdischarges (ADs) and after long-term potentiation (LTP) defined as synaptic enhancement without ADs. We studied�
Leung, L. Stan; Shen, Bixia
Cyclin S: a new member of the cyclin family plays a role in long-term memory.
Memory is thought to be subserved by structural and functional alteration in synaptic connectivity. But although neuronal plasticity requires gene expression, the identity of the proteins involved is largely unknown. Using the chick 1-day-old passive avoidance learning paradigm and differential display RNA fingerprinting, we identified 13 candidate genes which are upregulated in the intermediate medial hyperstriatum ventrale (IMHV), an area that has been correlated with the initial processing of memory formation. One of the induced genes is a new member of the cyclin family, with high homology to cyclin L (ania-6a). Analysis of the expression pattern of this gene after training revealed two time waves of induction: the first correlated with learning and initial memory process in the IMHV; the second correlated with memory consolidation, first in the IMHV, and then in the lobus paraolefactoris. There is a correlation between methylanthranilate (MeA) concentrations (the malaise substrate in the passive avoidance training procedure), the duration of memory and the expression level of cyclin S. While training chicks on low concentrations of MeA causes short-term memory and low expression level of cyclin S, high concentration of MeA induces long-term memory and high expression level of cyclin S in the IMHV. The role of cyclins in the regulation of neuronal-plasticity-related gene expression was overlooked, and it might serve as a key step in long-term memory formation. PMID:14725631
Edelheit, Sarit; Meiri, Noam
Spatial Memory and Long-Term Object Recognition Are Impaired by Circadian Arrhythmia and Restored by the GABAAAntagonist Pentylenetetrazole
Performance on many memory tests varies across the day and is severely impaired by disruptions in circadian timing. We developed a noninvasive method to permanently eliminate circadian rhythms in Siberian hamsters (Phodopussungorus) so that we could investigate the contribution of the circadian system to learning and memory in animals that are neurologically and genetically intact. Male and female adult hamsters were rendered arrhythmic by a disruptive phase shift protocol that eliminates cycling of clock genes within the suprachiasmatic nucleus (SCN), but preserves sleep architecture. These arrhythmic animals have deficits in spatial working memory and in long-term object recognition memory. In a T-maze, rhythmic control hamsters exhibited spontaneous alternation behavior late in the day and at night, but made random arm choices early in the day. By contrast, arrhythmic animals made only random arm choices at all time points. Control animals readily discriminated novel objects from familiar ones, whereas arrhythmic hamsters could not. Since the SCN is primarily a GABAergic nucleus, we hypothesized that an arrhythmic SCN could interfere with memory by increasing inhibition in hippocampal circuits. To evaluate this possibility, we administered the GABAA antagonist pentylenetetrazole (PTZ; 0.3 or 1.0 mg/kg/day) to arrhythmic hamsters for 10 days, which is a regimen previously shown to produce long-term improvements in hippocampal physiology and behavior in Ts65Dn (Down syndrome) mice. PTZ restored long-term object recognition and spatial working memory for at least 30 days after drug treatment without restoring circadian rhythms. PTZ did not augment memory in control (entrained) animals, but did increase their activity during the memory tests. Our findings support the hypothesis that circadian arrhythmia impairs declarative memory by increasing the relative influence of GABAergic inhibition in the hippocampus.
Ruby, Norman F.; Fernandez, Fabian; Garrett, Alex; Klima, Jessy; Zhang, Pei; Sapolsky, Robert; Heller, H. Craig
Does sustained ERP activity in posterior lexico-semantic processing areas during short-term memory tasks only reflect activated long-term memory?
Digital Repository Infrastructure Vision for European Research (DRIVER)
We challenge Ruchkin et al.'s claim in reducing short-term memory (STM) to the active part of long-term memory (LTM), by showing that their data cannot rule out the possibility that activation of posterior brain regions could also reflect the contribution of a verbal STM buffer.
Majerus, Steve; Linden, Martial; Collette, Fabienne; Salmon, Eric
Memory and long-term potentiation (LTP) dissociated: Normal spatial memory despite CA1 LTP elimination with Kv1.4 antisense
Digital Repository Infrastructure Vision for European Research (DRIVER)
Long-term potentiation (LTP) in the hippocampal slice preparation has been proposed as an in vitro model for long-term memory. However, correlation of LTP with memory in living animals has been difficult to demonstrate. Furthermore, in the last few years evidence has accumulated that dissociate the two. Because potassium channels might determine the weight of synapses in networks, we studied the role of Kv1.4, a presynaptic A-type voltage-dependent K+ channel, in both memory and LTP. Reverse ...
Meiri, Noam; Sun, Miao-kun; Segal, Zachary; Alkon, Daniel L.
Effects of Joint Attention on Long-Term Memory in 9-Month-Old Infants: An Event-Related Potentials Study
Joint attention develops during the first year of life but little is known about its effects on long-term memory. We investigated whether joint attention modulates long-term memory in 9-month-old infants. Infants were familiarized with visually presented objects in either of two conditions that differed in the degree of joint attention (high�
Kopp, Franziska; Lindenberger, Ulman
Long-term habituation (LTH) in the crab Chasmagnathus: a model for behavioral and mechanistic studies of memory
Digital Repository Infrastructure Vision for European Research (DRIVER)
A decade of studies on long-term habituation (LTH) in the crab Chasmagnathus is reviewed. Upon sudden presentation of a passing object overhead, the crab reacts with an escape response that habituates promptly and for at least five days. LTH proved to be an instance of associative memory and showed context, stimulus frequency and circadian phase specificity. A strong training protocol (STP) (�15 trials, intertrial interval (ITI) of 171 s) invariably yielded LTH, wh...
Maldonado, H.; Romano, A.; Tomsic, D.
Comparable Analysis of Long-term Memory of EUR/USD Based on Non-parametrical Statistics
Directory of Open Access Journals (Sweden)
Full Text Available Non-parameter statistical methods of classical R/S, revised R/S and V/S was proposed in long-term Memory of EUR/USD. It was concluded through comparable analysis that: (1 Through Normality Test of Return Sequences of EUR/USD Daily Closing Prices, the experimental results imply that bias of daily return sequences of EUR/USD is not equal to zero, and the curve appears to high peak and fat tail. (2 Jarque-Bera test is adopted. The estimated values reject the null hypothesis of normal distribution. (3 The paper estimates daily return series of EUR/USD using classical R/S method. The results show that Hurst exponent is equal to 0.612425; the statistical cycle is 160 days; the correlative scale is close to 1.3432. This study's conclusion was that long-term memory exists in daily return time series of EUR/USD is proved.Key words: rescaled range (R/S analysis; rescaled variance (V/S analysis; long-term memory
Yan-xi LI
The Sleep Elaboration-Awake Pruning (SEAP) theory of memory: long term memories grow in complexity during sleep and undergo selection while awake. Clinical, psychopharmacological and creative implications.
Long term memory (LTM) systems need to be adaptive such that they enhance an organism's reproductive fitness and self-reproducing in order to maintain their complexity of communications over time in the face of entropic loss of information. Traditional 'representation-consolidation' accounts conceptualize memory adaptiveness as due to memories being 'representations' of the environment, and the longevity of memories as due to 'consolidation' processes. The assumption is that memory representations are formed while an animal is awake and interacting with the environment, and these memories are consolidated mainly while the animal is asleep. So the traditional view of memory is 'instructionist' and assumes that information is transferred from the environment into the brain. By contrast, we see memories as arising endogenously within the brain's LTM system mainly during sleep, to create complex but probably maladaptive memories which are then simplified ('pruned') and selected during the awake period. When awake the LTM system is brought into a more intense interaction with past and present experience. Ours is therefore a 'selectionist' account of memory, and could be termed the Sleep Elaboration-Awake Pruning (or SEAP) theory. The SEAP theory explains the longevity of memories in the face of entropy by the tendency for memories to grow in complexity during sleep; and explains the adaptiveness of memory by selection for consistency with perceptions and previous memories during the awake state. Sleep is therefore that behavioural state during which most of the internal processing of the system of LTM occurs; and the reason sleep remains poorly understood is that its primary activity is the expansion of long term memories. By re-conceptualizing the relationship between memory, sleep and the environment; SEAP provides a radically new framework for memory research, with implications for the measurement of memory and the design of empirical investigations in clinical, psychopharmacological and creative domains. For example, it would be predicted that states of insufficient alertness such as delirium would produce errors of commission (memory distortion and false memories, as with psychotic delusions), while sleep deprivation would produce errors of memory omission (memory loss). Ultimately, the main argument in favour of SEAP is that long term memory must be a complex adaptive system, and complex systems arise, are selected and sustained according to the principles of systems theory; and therefore LTM cannot be functioning in the way assumed by 'representation-consolidation' theories. PMID:19349123
Charlton, Bruce G; Andras, Peter
The role of reconsolidation and the dynamic process of long-term memory formation and storage
Directory of Open Access Journals (Sweden)
Full Text Available It is becoming increasingly clear that the processes of memory formation and storage are exquisitely dynamic. Elucidating the nature and temporal evolution of the biological changes that accompany encoding, storage and retrieval is key to understand memory formation. For explicit or medial temporal lobe-dependent memories that form after a discrete event and are stored for a long time, the physical changes underlying the encoding and processing of the information (memory trace or engram remain in a fragile state for some time. However, over time, the new memory becomes increasingly resistant to disruption until it is consolidated. Retrieval or reactivation of an apparently consolidated memory can render the memory labile again, and reconsolidation is the process that occurs to mediate its restabilization. Reconsolidation also evolves with the age of the memory: Young memories are sensitive to postreactivation disruption, but older memories are more resistant. Why does a memory become labile again if it is retrieved or reactivated? Here I suggest that the main function of reconsolidation is to contribute to the lingering consolidation process and mediate memory strengthening. I also discuss the literature and results regarding the influence of the passage of time on the reconsolidation of memory. These points have important implications for the use of reconsolidation in therapeutic settings.
Memory formation and long-term retention in humans and animals: convergence towards a transformation account of hippocampal-neocortical interactions.
Historically, the hippocampus has been viewed as a temporary memory structure. Consistent with the central premise of standard consolidation theory (SCT), a memory is initially hippocampus-dependent but, over time, it undergoes a consolidation process and eventually becoming represented in a distributed cortical network independent of the hippocampus. In this paper, we review evidence that is incompatible with each of the following essential features of SCT that are derived from its central premise: (1) Hippocampal damage reliably produces temporally graded retrograde amnesia, (2) all declarative explicit memories are equivalent with respect to consolidation, (3) consolidation entails a process of duplication in which a particular cortically based memory is identical to the hippocampus-dependent memory from which it derived, (4) consolidated memories are permanent and immutable. We propose an alternative hypothesis that assumes a transformation process and changes in the memory over time. Building on multiple trace theory (Nadel & Moscovitch, 1997), the transformation hypothesis contains three key elements that differentiate it from SCT: (1) An initially formed memory, which is assumed to be episodic and context-bound, remains dependent on the hippocampus for as long as it is available, (2) with time and experience, a hippocampal memory supports the development, in neocortex, of a less integrated, schematic version, which retains the gist of the original memory, but few of its contextual details, (3) there is a dynamic interplay between the two types of memory such that one or another may be dominant, depending on the circumstances at retrieval. Evidence is provided in support of the transformation hypothesis, which is advanced as a framework for unifying the seemingly disparate results of studies of anterograde and retrograde memory in the animal and human literatures. PMID:20430044
Winocur, Gordon; Moscovitch, Morris; Bontempi, Bruno
The Value of Animations in Biology Teaching: A Study of Long-Term Memory Retention
Digital Repository Infrastructure Vision for European Research (DRIVER)
Previous work has established that a narrated animation is more effective at communicating a complex biological process (signal transduction) than the equivalent graphic with figure legend. To my knowledge, no study has been done in any subject area on the effectiveness of animations versus graphics in the long-term retention of information, a primary and critical issue in studies of teaching and learning. In this study, involving 393 student responses, three different animations and two grap...
O Day, Danton H.
Attention Problems, Phonological Short-Term Memory, and Visuospatial Short-Term Memory: Differential Effects on Near- and Long-Term Scholastic Achievement
The current study examined individual differences in children's phonological and visuospatial short-term memory as potential mediators of the relationship among attention problems and near- and long-term scholastic achievement. Nested structural equation models revealed that teacher-reported attention problems were associated negatively with�
Sarver, Dustin E.; Rapport, Mark D.; Kofler, Michael J.; Scanlan, Sean W.; Raiker, Joseph S.; Altro, Thomas A.; Bolden, Jennifer
Errors in nonword repetition: bridging short- and long-term memory
Digital Repository Infrastructure Vision for European Research (DRIVER)
According to the working memory model, the phonological loop is the component of working memory specialized in processing and manipulating limited amounts of speech-based information. The Children's Test of Nonword Repetition (CNRep) is a suitable measure of phonological short-term memory for English-speaking children, which was validated by the Brazilian Children's Test of Pseudoword Repetition (BCPR) as a Portuguese-language version. The objectives of the present study were: i) to investiga...
Santos F.H.; Bueno O.F.A.; Gathercole S.E.
The Effect of Synchronized Forced Running with Chronic Stress on Short, Mid and Long- term Memory in Rats
Directory of Open Access Journals (Sweden)
Full Text Available Purpose: Impairment of learning and memory processes has been demonstrated by many studies using different stressors. Other reports suggested that exercise has a powerful behavioral intervention to improve cognitive function and brain health. In this research, we investigated protective effects of treadmill running on chronic stress�induced memory deficit in rats.Methods: Fifty male Wistar rats were randomly divided into five groups (n=10 as follows: Control (Co, Sham (Sh, Stress (St, Exercise (Ex and Stress and Exercise (St & Ex groups. Chronic restraint stress was applied by 6h/day/21days and also treadmill running at a speed 20-21�m/min for 1h/day/21days. Memory function was evaluated by the passive avoidance test in different intervals (1, 7 and 21 days after foot shock.Results: Our results showed that: 1 Although exercise alone showed beneficial effects especially on short and mid-term memory (P<0.05 in comparison with control group, but synchronized exercise with stress had not significantly improved short, mid and long-term memory deficit in stressed rats. 2 Short and mid-term memory deficit was significantly (P<0.05 observed in synchronized exercise with stress and stress groups with respect to normal rats. 3 Memory deficit in synchronized exercise with stress group was nearly similar to stressed rats. 4 Helpful effects of exercise were less than harmful effects of stress when they were associated together.Conclusion: The data correspond to the possibility that although treadmill running alone has helpful effects on learning and memory consolidation, but when it is synchronized with stress there is no significant benefit and protective effects in improvement of memory deficit induced by chronic stress. However, it is has a better effect than no training on memory deficit in stressed rats.
Maryam Radahmadi
Long-Term Memory Shapes the Primary Olfactory Center of an Insect Brain
The storage of stable memories is generally considered to rely on changes in the functional properties and/or the synaptic connectivity of neural networks. However, these changes are not easily tractable given the complexity of the learning procedures and brain circuits studied. Such a search can be narrowed down by studying memories of specific�
Hourcade, Benoit; Perisse, Emmanuel; Devaud, Jean-Marc; Sandoz, Jean-Christophe
Dopamine interferes with appetitive long-term memory formation in honey bees.
Studies in vertebrates and invertebrates have proved the instructive role that different biogenic amines play in the neural representation of rewards and punishments during associative learning. Results from diverse arthropods and using different learning paradigms initially agreed that dopamine (DA) is needed for aversive learning and octopamine (OA) is needed for appetitive learning. However, the notion that both amines constitute separate pathways for appetitive and aversive learning is changing. Here, we asked whether DA, so far only involved in aversive memory formation in honey bees, does also modulate appetitive memory. Using the well characterized appetitive olfactory conditioning of the proboscis extension reflex (PER), we show that DA impairs appetitive memory consolidation. In addition, we found that blocking DA receptors enhances appetitive memory. These results are consistent with the view that aversive and appetitive components interact during learning and memory formation to ensure adaptive behavior. PMID:24076013
Klappenbach, Mart�n; Kaczer, Laura; Locatelli, Fernando
Mind bomb-1 is an essential modulator of long-term memory and synaptic plasticity via the Notch signaling pathway
Directory of Open Access Journals (Sweden)
Full Text Available Abstract Background Notch signaling is well recognized as a key regulator of the neuronal fate during embryonic development, but its function in the adult brain is still largely unknown. Mind bomb-1 (Mib1 is an essential positive regulator in the Notch pathway, acting non-autonomously in the signal-sending cells. Therefore, genetic ablation of Mib1 in mature neuron would give valuable insight to understand the cell-to-cell interaction between neurons via Notch signaling for their proper function. Results Here we show that the inactivation of Mib1 in mature neurons in forebrain results in impaired hippocampal dependent spatial memory and contextual fear memory. Consistently, hippocampal slices from Mib1-deficient mice show impaired late-phase, but not early-phase, long-term potentiation and long-term depression without change in basal synaptic transmission at SC-CA1 synapses. Conclusions These data suggest that Mib1-mediated Notch signaling is essential for long-lasting synaptic plasticity and memory formation in the rodent hippocampus.
Yoon Ki-Jun
Accelerated long-term forgetting (ALF) and transient epileptic amnesia (TEA): two cases of epilepsy-related memory disorder.
Temporal lobe epilepsy (TLE) has long been associated with memory impairment. Recently, two specific forms of memory complaint in this population have been identified: accelerated long-term forgetting (ALF) and transient epileptic amnesia (TEA). This paper presents neuropsychological data (standard neuropsychological tests and experimental measures) on two patients who presented in the epilepsy clinic with seemingly similar subjective reports of profound memory difficulties. This paper illustrates the differences between TEA and ALF. Our focus was on measuring long-term forgetting utilizing a novel visual and verbal test protocol, with responses elicited via verbal prompts over the telephone at intervals up to 30 days. Whereas patient SK had neuropsychological test evidence of problems with learning plus ALF at short and long intervals without clinical evidence of TEA, patient EB had clinically convincing TEA without neuropsychological test evidence of ALF. In particular, SK showed accelerated forgetting while EB did not. This detailed case work develops our understanding of ALF measurement and demonstrates that ALF and TEA can be dissociated. PMID:22658945
Kemp, Steven; Illman, Nathan A; Moulin, Chris J A; Baddeley, Alan D
Memory and learning sequelae in long-term survivors of acute lymphoblastic leukemia: Association with attention deficits
International Nuclear Information System (INIS)
A systematic study of verbal and nonverbal memory and learning was undertaken in long-term survivors of acute lymphoblastic leukemia to assess the incidence and pattern of impairments and to determine the relationship between these deficits and computed tomography (CT) brain scan abnormalities. Twenty-three children who had received cranial irradiation (2,400 cGy) and intrathecal chemotherapy as central nervous system (CNS) preventive therapy and who were off all therapy for at least 4 years were evaluated. On the basis of their CT brain scan findings, patients were divided into three groups: those with intracerebral calcifications (n = 5), those with cortical atrophy (n = 8), and those with normal CT findings (n = 10). Significant deficits in verbal memory (p less than 0.025) and verbal learning (p less than 0.05) were observed that were associated with the presence and type of CT brain scan abnormalities; the greatest impairments were observed in patients with calcifications. No significant differences between CT scan groups were found for nonverbal memory and learning. Previous evaluation of attentional processing in these patients using reaction time tests had revealed the presence of deficits primarily in the ability to sustain attention. Combining those data with findings from the present study showed that memory impairments, particularly those in short-term memory, were primarily attributable to an underlying attentional defect that affect the encoding stage of memory processing
Comparable Analysis of Long-term Memory of EUR/USD Based on Non-parametrical Statistics
Digital Repository Infrastructure Vision for European Research (DRIVER)
Non-parameter statistical methods of classical R/S, revised R/S and V/S was proposed in long-term Memory of EUR/USD. It was concluded through comparable analysis that: (1) Through Normality Test of Return Sequences of EUR/USD Daily Closing Prices, the experimental results imply that bias of daily return sequences of EUR/USD is not equal to zero, and the curve appears to high peak and fat tail. (2) Jarque-Bera test is adopted. The estimated values reject the null hypothesis of normal distribut...
Huang, Fei-xue; Jin, Jian-dong; Li, Yan-xi
A spatially supported forced-choice recognition test reveals children's long-term memory for newly learned word forms.
Children's memories for the link between a newly trained word and its referent have been the focus of extensive past research. However, memory for the word form itself is rarely assessed among preschool-age children. When it is, children are typically asked to verbally recall the forms, and they generally perform at floor on such tests. To better measure children's memory for word forms, we aimed to design a more sensitive test that required recognition rather than recall, provided spatial cues to off-set the phonological memory demands of the test, and allowed pointing rather than verbal responses. We taught 12 novel word-referent pairs via ostensive naming to sixteen 4- to 6-year-olds and measured their memory for the word forms after a week-long retention interval using the new spatially supported form recognition test. We also measured their memory for the word-referent links and the generalization of the links to untrained referents with commonly used recognition tests. Children demonstrated memory for word forms at above chance levels; however, their memory for forms was poorer than their memory for trained or generalized word-referent links. When in error, children were no more likely to select a foil that was a close neighbor to the target form than a maximally different foil. Additionally, they more often selected correct forms that were among the first six than the last six to be trained. Overall, these findings suggest that children are able to remember word forms after a limited number of ostensive exposures and a long-term delay. However, word forms remain more difficult to learn than word-referent links and there is an upper limit on the number of forms that can be learned within a given period of time. PMID:24639660
Gordon, Katherine R; McGregor, Karla K
Event-related potential correlates of long-term memory for briefly presented faces.
Electrophysiological studies have investigated the nature of face recognition in a variety of paradigms; some have contrasted famous and novel faces in explicit memory paradigms, others have repeated faces to examine implicit memory/priming. If the general finding that implicit memory can last for up to several months also holds for novel faces, a reliable measure of it could have practical application for eyewitness testimony, given that explicit measures of eyewitness memory have at times proven fallible. The current study aimed to determine whether indirect behavioral and electrophysiological measures might yield reliable estimates of face memory over longer intervals than have typically been obtained with priming manipulations. Participants were shown 192 faces and then tested for recognition at four test delays ranging from immediately up to 1 week later. Three event-related brain potential components (e.g., N250r, N400f, and LPC) varied with memory measures although only the N250r varied regardless of explicit recognition, that is, with both repetition and recognition. PMID:15904542
Joyce, Carrie A; Kutas, Marta
Transgenic Overexpression of the Type I Isoform of Neuregulin 1 Affects Working Memory and Hippocampal Oscillations but not Long-term Potentiation
Digital Repository Infrastructure Vision for European Research (DRIVER)
Neuregulin 1 (NRG1) is a growth factor involved in neurodevelopment and plasticity. It is a schizophrenia candidate gene, and hippocampal expression of the NRG1 type I isoform is increased in the disorder. We have studied transgenic mice overexpressing NRG1 type I (NRG1tg-type I) and their wild-type littermates and measured hippocampal electrophysiological and behavioral phenotypes. Young NRG1tg-type I mice showed normal memory performance, but in older NRG1tg-type I mice, hippocampus-depende...
Deakin, Inga H.; Nissen, Wiebke; Law, Amanda J.; Lane, Tracy; Kanso, Riam; Schwab, Markus H.; Nave, Klaus-armin; Lamsa, Karri P.; Paulsen, Ole; Bannerman, David M.; Harrison, Paul J.
Genetic Enhancement of Memory and Long-Term Potentiation but Not CA1 Long-Term Depression in NR2B Transgenic Rats
Digital Repository Infrastructure Vision for European Research (DRIVER)
One major theory in learning and memory posits that the NR2B gene is a universal genetic factor that acts as rate-limiting molecule in controlling the optimal NMDA receptor's coincidence-detection property and subsequent learning and memory function across multiple animal species. If so, can memory function be enhanced via transgenic overexpression of NR2B in another species other than the previously reported mouse species? To examine these crucial issues, we generated transgenic rats in whic...
Wang, Deheng; Cui, Zhenzhong; Zeng, Qingwen; Kuang, Hui; Wang, L. Phillip; Tsien, Joe Z.; Cao, Xiaohua
Mice overexpressing type 1 adenylyl cyclase show enhanced spatial memory flexibility in the absence of intact synaptic long-term depression
Digital Repository Infrastructure Vision for European Research (DRIVER)
There is significant interest in understanding the contribution of intracellular signaling and synaptic substrates to memory flexibility, which involves new learning and suppression of obsolete memory. Here, we report that enhancement of Ca2+-stimulated cAMP signaling by overexpressing type 1 adenylyl cyclase (AC1) facilitated long-term potentiation (LTP) but impaired long-term depression (LTD) at the hippocampal Shaffer collateral-CA1 synapses. However, following the induction of LTP, low-fr...
Zhang, Ming; Wang, Hongbing
Lead (Pb+2) impairs long-term memory and blocks learning-induced increases in hippocampal protein kinase C activity
International Nuclear Information System (INIS)
The long-term storage of information in the brain known as long-term memory (LTM) depends on a variety of intracellular signaling cascades utilizing calcium (Ca2+) and cyclic adenosine monophosphate as second messengers. In particular, Ca+2/phospholipid-dependent protein kinase C (PKC) activity has been proposed to be necessary for the transition from short-term memory to LTM. Because the neurobehavioral toxicity of lead (Pb+2) has been associated to its interference with normal Ca+2 signaling in neurons, we studied its effects on spatial learning and memory using a hippocampal-dependent discrimination task. Adult rats received microinfusions of either Na+ or Pb+2 acetate in the CA1 hippocampal subregion before each one of four training sessions. A retention test was given 7 days later to examine LTM. Results suggest that intrahippocampal Pb+2 did not affect learning of the task, but significantly impaired retention. The effects of Pb+2 selectively impaired reference memory measured in the retention test, but had no effect on the general performance because it did not affect the latency to complete the task during the test. Finally, we examined the effects of Pb+2 on the induction of hippocampal Ca+2/phospholipid-dependent PKC activity during acquisition training. The results showed that Pb+2 interfered with the learning-induced activation of Ca+2/phospholipid-dependent PKC on day 3 of acquisition. Overall, our results indicate that Pb+2 causes cognitive impairments in adult rats and that such effects might be subserved by interference with Ca+2-related signaling mechanisms required for normal LTM
On the scaling ranges of detrended fluctuation analysis for long-term memory correlated short series of data
We examine the scaling regime for the detrended fluctuation analysis (DFA)-the most popular method used to detect the presence of long-term memory in data and the fractal structure of time series. First, the scaling range for DFA is studied for uncorrelated data as a function of time series length L and the correlation coefficient of the linear regression R2 at various confidence levels. Next, a similar analysis for artificial short series of data with long-term memory is performed. In both cases the scaling range ? is found to change linearly-both with L and R2. We show how this dependence can be generalized to a simple unified model describing the relation ?=?(L,R2,H) where H (1/2?H?1) stands for the Hurst exponent of the long range autocorrelated signal. Our findings should be useful in all applications of DFA technique, particularly for instantaneous (local) DFA where a huge number of short time series has to be analyzed at the same time, without possibility of checking the scaling range in each of them separately.
Grech, Dariusz; Mazur, Zygmunt
An optical model for implementing Parrondo�s game and designing stochastic game with long-term memory
International Nuclear Information System (INIS)
Highlights: ? Using a photon propagating through a designed array of beam splitters to simulate Parrondo�s game paradox. ? Design the optical flowchart for implementing Parrondo history-dependent game paradox. ? Design new game with long-term memory on a designed tree lattice and loop lattice. - Abstract: An optical model for a photon propagating through a designed array of beam splitters is developed to give a physical implementation of Parrondo�s game and Parrondo�s history-dependent game. The winner in this optical model is a photon passed the beam splitter. The loser is a photon being reflected by the beam splitter. The optical beam splitter is the coin-tosser. We designed new games with long-term memory by using this optical diagram method. The optical output of the combined game of two losing games could be a win, or a loss, or an oscillation between win and loss. The modern technology to implement this optical model is well developed. A circularly polarized photon is a possible candidate for this physical implementation in laboratory.
Posterior parietal cortex and long-term memory: some data from laboratory animals.
The posterior parietal cortex (PPC) was long viewed as just involved in the perception of spatial relationships between the body and its surroundings and of movements related to them. In recent years the PPC has been shown to participate in many other cognitive processes, among which working memory and the consolidation and retrieval of episodic memory. The neurotransmitter and other molecular processes involved have been determined to a degree in rodents. More research will no doubt determine the extent to which these findings can be extrapolated to primates, including humans. In these there appears to be a paradox: imaging studies strongly suggest an important participation of the PPC in episodic memory, whereas lesion studies are much less suggestive, let alone conclusive. The data on the participation of the PPC in episodic memory so far do not permit any conclusion as to what aspect of consolidation and retrieval it handles in addition to those dealt with by the hippocampus and basolateral amygdala, if any. PMID:22375107
Myskiw, Jociane C; Izquierdo, Iv�n
Aversive Olfactory Learning and Associative Long-Term Memory in "Caenorhabditis elegans"
The nematode "Caenorhabditis elegans" ("C. elegans") adult hermaphrodite has 302 invariant neurons and is suited for cellular and molecular studies on complex behaviors including learning and memory. Here, we have developed protocols for classical conditioning of worms with 1-propanol, as a conditioned stimulus (CS), and hydrochloride (HCl) (pH�
Amano, Hisayuki; Maruyama, Ichiro N.
Energy Technology Data Exchange (ETDEWEB)
Anisomycin is an effective inhibitor of cerebral protein synthesis in mice and is also an effective amnestic agent for both passive and active behavioral tasks. From use of anisomycin in combination with a variety of stimulant and depressant drugs, we conclude that the level of arousal following acquisition plays an important role in determining the duration and the rate of the biosynthetic phase of memory formation. While we have interpreted the experiments with anisomycin as evidence for an essential role of protein in memory storage, others have suggested that side effects of inhibitors of protein synthesis on catecholamine metabolism are the main cause of amnesia. Several experiments were therefore done to compare the effects of anisemycin and catecholamine inhibitors on memory. We conclude that anisomycin's principal amnestic mechanism does not involve inhibition of the catecholamine system. The results strengthen our conclusion that protein synthesis is an essential component for longterm memory trace formation. Also, it is suggested that proteins synthesized in the neuronal cell body are used, in conjunction with other molecules, to produce permanent and semi-permanent anatomical changes.
Bennett, E.L.; Rosenzweig, M.R.; Flood, J.F.
Synthetic amyloid-? oligomers impair long-term memory independently of cellular prion protein
Digital Repository Infrastructure Vision for European Research (DRIVER)
Inability to form new memories is an early clinical sign of Alzheimer�s disease (AD). There is ample evidence that the amyloid-? (A?) peptide plays a key role in the pathogenesis of this disorder. Soluble, bio-derived oligomers of A? are proposed as the key mediators of synaptic and cognitive dysfunction, but more tractable models of A??mediated cognitive impairment are needed. Here we report that, in mice, acute intracerebroventricular injections of synthetic A?1�42 oligomers impa...
Balducci, Claudia; Beeg, Marten; Stravalaci, Matteo; Bastone, Antonio; Sclip, Alessandra; Biasini, Emiliano; Tapella, Laura; Colombo, Laura; Manzoni, Claudia; Borsello, Tiziana; Chiesa, Roberto; Gobbi, Marco; Salmona, Mario; Forloni, Gianluigi
Reconsolidation of a context long-term memory in the terrestrial snail requires protein synthesis
Digital Repository Infrastructure Vision for European Research (DRIVER)
We investigated the influence of the protein synthesis blocker anisomycin on contextual memory in the terrestrial snail Helix. Prior to the training session, the behavioral responses in two contexts were similar. Two days after a session of electric shocks (5 d) in one context only, the context conditioning was observed as the significant difference of behavioral response amplitudes in two contexts. On the day following testing of context learning, a session of �reminding� was performed, ...
Gainutdinova, Tatiana H.; Tagirova, Rosa R.; Ismailova, Asja I.; Muranova, Lyudmila N.; Samarova, Elena I.; Gainutdinov, Khalil L.; Balaban, Pavel M.
Neurabin Contributes to Hippocampal Long-Term Potentiation and Contextual Fear Memory
Digital Repository Infrastructure Vision for European Research (DRIVER)
Neurabin is a scaffolding protein that interacts with actin and protein phosphatase-1. Highly enriched in the dendritic spine, neurabin is important for spine morphogenesis and synaptic formation. However, less is known about the role of neurabin in hippocampal plasticity and its possible effect on behavioral functions. Using neurabin knockout (KO) mice, here we studied the function of neurabin in hippocampal synaptic transmission, plasticity and behavioral memory. We demonstrated that neurab...
Wu, Long-jun; Ren, Ming; Wang, Hansen; Kim, Susan S.; Cao, Xiaoyan; Zhuo, Min
Mangiferin, a naturally occurring glucoxilxanthone improves long-term object recognition memory in rats.
Mangiferin (2-beta-D-glucopyranosyl-1,3,6,7-tetrahydroxyxanthone) is a xanthone widely distributed in higher plants showing antioxidative, antiviral, anticancer, antidiabetic, immunomodulatory, hepatoprotective, and analgesic effects. In the present study, we have investigated the effects of systemic administration of mangiferin on behavioral outcomes of neurological function in normal rats. A single intraperitoneal injection of mangiferin (10, 50, or 100mg/kg body weight) enhanced novel object recognition (NOR) memory when given immediately post-training. The administration of mangiferin 6h post-training did not affect NOR memory. There were no significant differences between groups in the total time exploring both objects, indicating that mangiferin did not affect locomotion or motivation. Mangiferin stimulated cell proliferation and induced a significant increase in the supernatant levels of nerve growth factor (NGF) and tumor necrosis factor (TNF)-alpha in vitro in human U138-MG glioblastoma cells. The results indicate that mangiferin enhances recognition memory through a mechanism that might involve an increase in neurotrophin and cytokine levels. PMID:20303935
Pardo Andreu, Gilberto L; Maurmann, Natasha; Reolon, Gustavo Kellermann; de Farias, Caroline B; Schwartsmann, Gilberto; Delgado, Ren�; Roesler, Rafael
Chronic administration of sulbutiamine improves long term memory formation in mice: possible cholinergic mediation.
Thiamine deficiency in both man and animals is known to produce memory dysfunction and cognitive disorders which have been related to an impairment of cholinergic activity. The present experiment was aimed at testing whether, inversely, chronic administration of large doses of sulbutiamine would have a facilitative effect on memory and would induce changes in central cholinergic activity. Accordingly mice received 300 mg/kg of sulbutiamine daily for 10 days. They were then submitted to an appetitive operant level press conditioning test. When compared to control subjects, sulbutiamine treated mice learned the task at the same rate in a single session but showed greatly improved performance when tested 24 hr after partial acquisition of the same task. Parallel neurochemical investigations showed that the treatment induced a slight (+ 10%) but significant increase in hippocampal sodium-dependent high affinity choline uptake. The present findings and previous results suggest that sulbutiamine improves memory formation and that this behavioral effect could be mediated by an increase in hippocampal cholinergic activity. PMID:4059305
Micheau, J; Durkin, T P; Destrade, C; Rolland, Y; Jaffard, R
Hippocampal inactivation with TTX impairs long-term spatial memory retrieval and modifies brain metabolic activity.
Functional inactivation techniques enable studying the hippocampal involvement in each phase of spatial memory formation in the rat. In this study, we applied tetrodotoxin unilaterally or bilaterally into the dorsal hippocampus to evaluate the role of this brain structure in retrieval of memories acquired 28 days before in the Morris water maze. We combined hippocampal inactivation with the assessment of brain metabolism using cytochrome oxidase histochemistry. Several brain regions were considered, including the hippocampus and other related structures. Results showed that both unilateral and bilateral hippocampal inactivation impaired spatial memory retrieval. Hence, whereas subjects with bilateral hippocampal inactivation showed a circular swim pattern at the side walls of the pool, unilateral inactivation favoured swimming in the quadrants adjacent to the target one. Analysis of cytochrome oxidase activity disclosed regional differences according to the degree of hippocampal functional blockade. In comparison to control group, animals with bilateral inactivation showed increased CO activity in CA1 and CA3 areas of the hippocampus during retrieval, while the activity of the dentate gyrus substantially decreased. However, unilateral inactivated animals showed decreased CO activity in Ammon's horn and the dentate gyrus. This study demonstrated that retrieval recruits differentially the hippocampal subregions and the balance between them is altered with hippocampal functional lesions. PMID:23724089
Conejo, N�lida Mar�a; Cimadevilla, Jos� Manuel; Gonz�lez-Pardo, H�ctor; M�ndez-Couz, Marta; Arias, Jorge Luis
Understanding the neurobiological mechanisms of learning and memory: Memory systems of the brain, long term potentiation and synaptic...
Digital Repository Infrastructure Vision for European Research (DRIVER)
El fen�meno de LTP es una forma de plasticidad sin�ptica ampliamente aceptado como un modelo de estabilizaci�n de sinapsis en procesos neurobiol�gicos como el desarrollo del SNC y el fen�meno de aprendizaje y memoria. Desde su descubrimiento por Bliss y Lomo (1973), el fen�meno de potenciaci�n a largo plazo (PLP) o LTP (Long-Term Potentiation, por sus siglas en ingl�s) ha sido definido convencionalmente como la estimulaci�n aferente de alta frecuenc...
A Dynamical Model for Information Retrieval and Emergence of Scale-Free Clusters in a Long Term Memory Network
The classical forms of knowledge representation fail when a strong dynamical interconnection between system and environment comes into play. We propose here a model of information retrieval derived from the Kintsch-Ericsson scheme, based upon a long term memory (LTM) associative net whose structure changes in time according to the textual content of the analyzed documents. Both the theoretical analysis carried out by using simple statistical tools and the tests show the appearing of typical power-laws and the net configuration as a scale-free graph. The information retrieval from LTM shows that the entire system can be considered to be an information amplifier which leads to the emergence of new cognitive structures. It has to be underlined that the expanding of the semantic domain regards the user-network as a whole system.
Licata, Ignazio
Delayed emergence of effects of memory-enhancing drugs: implications for the dynamics of long-term memory.
Digital Repository Infrastructure Vision for European Research (DRIVER)
Many theories of memory postulate that processing of information outlasts the learning situation and involves several different physiological substrates. If such physiologically distinct mechanisms or stages of memory do in fact exist, they should be differentially affected by particular experimental manipulations. Accordingly, a selective improvement of the processes underlying short-term memory should be detectable only while the information is encoded in the short-term mode, and a selectiv...
Mondadori, C.; Hengerer, B.; Ducret, T.; Borkowski, J.
Consolidation of long-term memory by insulin in Lymnaea is not brought about by changing the number of insulin receptors
Digital Repository Infrastructure Vision for European Research (DRIVER)
The pond snail Lymnaea stagnalis learns taste aversion and consolidates it into long-term memory (LTM). This is referred to as conditioned taste aversion (CTA). The superfusion of molluscan insulin-related peptides (MIPs) over the isolated snail brain causes a long-term enhancement of synaptic input between the cerebral giant cell and the B1 buccal motor neuron. This enhancement is hypothesized to underlie CTA. The synaptic enhancement caused by the superfusion of MIPs can be blocked by the a...
Hatakeyama, Dai; Okuta, Akiko; Otsuka, Emi; Lukowiak, Ken; Ito, Etsuro
Monosynaptic connections made by the sensory neurons of the gill- and siphon-withdrawal reflex in Aplysia participate in the storage of long-term memory for sensitization
Digital Repository Infrastructure Vision for European Research (DRIVER)
We have found that in the gill- and siphon- withdrawal reflex of Aplysia, the memory for short-term sensitization grades smoothly into long-term memory with increased amounts of sensitization training. One cellular locus for the storage of the memory underlying short-term sensitization is the set of monosynaptic connections between the siphon sensory cells and the gill and siphon motor neurons. We have now also found that these same monosynaptic connections participate in the storage of the m...
Frost, William N.; Castellucci, Vincent F.; Hawkins, Robert D.; Kandel, Eric R.
Learning to never forget � Time scales and specificity of long-term memory of a motor skill
Directory of Open Access Journals (Sweden)
Full Text Available Despite anecdotal reports that humans retain acquired motor skills for many years, if not a lifetime, long-term memory of motor skills has received little attention. While numerous neuroimaging studies showed practice-induced cortical plasticity, the behavioral correlates, what is retained and also what is forgotten, are little understood. This longitudinal case study on four subjects presents detailed kinematic analyses of humans practicing a bimanual polyrhythmic task over 2 months with retention tests after 6 months and, for two subjects, after 8 years. Results showed that individuals not only retained the task, but also reproduced their individual �style� of performance, even after 8 years. During practice, variables such as the two hands� frequency ratio and relative phase changed at different rates, indicative of multiple time-scales of neural processes. Frequency leakage across hands, reflecting inter manual crosstalk, attenuated at a significantly slower rate and was the only variable not maintained after 8 years. Complementing recent findings on neuroplasticity in grey and white matter, our study presents new behavioral evidence that highlights the multi-scale process of practice-induced changes and its remarkable persistence. Results suggest that motor memory may comprise not only higher-level task achievement but also individual kinematic signatures.
The Effects of Intersensory Redundancy on Attention and Memory: Infants� Long-Term Memory for Orientation in Audiovisual Events
Digital Repository Infrastructure Vision for European Research (DRIVER)
This research examined the effects of bimodal audiovisual and unimodal visual stimulation on infants� memory for the visual orientation of a moving toy hammer following a 5-min, 2-week, or 1-month retention interval. According to the intersensory redundancy hypothesis (L. E. Bahrick & R. Lickliter, 2000; L. E. Bahrick, R. Lickliter, & R. Flom, 2004) detection of and memory for nonredundantly specified properties, including the visual orientation of an event, are facilitated in unimodal stim...
Flom, Ross; Bahrick, Lorraine E.
Understanding the neurobiological mechanisms of learning and memory: Memory systems of the brain, long term potentiation and synaptic...
Directory of Open Access Journals (Sweden)
Full Text Available El fen�meno de LTP es una forma de plasticidad sin�ptica ampliamente aceptado como un modelo de estabilizaci�n de sinapsis en procesos neurobiol�gicos como el desarrollo del SNC y el fen�meno de aprendizaje y memoria. Desde su descubrimiento por Bliss y Lomo (1973, el fen�meno de potenciaci�n a largo plazo (PLP o LTP (Long-Term Potentiation, por sus siglas en ingl�s ha sido definido convencionalmente como la estimulaci�n aferente de alta frecuencia que es capaz de despolarizar la c�lula postsin�ptica, a trav�s de la activaci�n de receptores glutama�rgicos, con la resultante entrada de calcio a la neurona postsin�ptica. Este evento neurobiol�gico produce un incremento intracelular en la concentraci�n de calcio [(Cai] que induce la activaci�n de diferentes sistemas moleculares de se�alamiento intracelular (AMPc, prote�nas cinasas, fosforilaci�n de prote�nas intracelulares que conlleva a una alteraci�n de la actividad postsin�ptica y/o presin�ptica, dando por resultado un persistente incremento de respuesta sin�ptica espec�fica dependiente de la activaci�n del receptor glutama�rgico NMDA...
Juan Carlos Calva
Long-term memory formation in the chick requires mobilization of ryanodine-sensitive intracellular calcium stores.
Training chicks (Gallus domesticus) on a one-trial passive avoidance task results in transient and time-dependent enhanced increases in N-methyl-d-aspartate- or alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate-stimulated intracellular calcium concentration in synaptoneurosomes isolated from a specific forebrain region, the intermediate medial hyperstriatum ventrale. This increase could result from either calcium entry from the extracellular medium or from mobilization of intracellular calcium stores. We have therefore examined the effects of dantrolene, an inhibitor of calcium release from the intracellular ryanodine-sensitive store, on these processes. Dantrolene, 50 nmol per hemisphere injected intracerebrally 30 min pre- or 30 min posttraining, blocked longer term memory for the passive avoidance task, whereas memory for the task was unaffected when dantrolene was injected at earlier or later times. Preincubation of synaptoneurosomes, isolated from the intermediate hyperstriatum ventrale 10 min after training, with 100 nM dantrolene abolished the enhanced training-induced increase in intracellular calcium concentration elicited by 0.5 mM N-methyl-d-aspartate. By contrast, the training-induced enhancement of the alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate-stimulated increase in intracellular calcium concentration in synaptoneurosomes prepared 6 h posttraining was unaffected by preincubation with dantrolene, which was not amnestic at this time. Calcium release from ryanodine-sensitive intracellular stores may thus be a necessary stage in the early phase of the molecular cascade leading to the synaptic modulation required for long-term memory storage. PMID:11300735
Salinska, E J; Bourne, R C; Rose, S P
Comparison of the Effects of Dose-dependent Zinc Chloride on Short-term and Long-term Memory in Young Male Rats
Digital Repository Infrastructure Vision for European Research (DRIVER)
The aim of the present study was to evaluate the effects of dose-dependent of zinc chloride on short-term and long-term memory in a shuttle box. Young Wistar rats (94�10 g) (age 27-30 days) consumed zinc chloride drinking water in five different doses (20, 30, 50, 70 and 100 mg kg-1day-1) for two weeks by gavage. After 14 days on experimental diets, a shuttle box used to test short- and long-term memory. Two criteria considering for behavioral test, including latency in...
Moazedi, A. A.; Ghotbeddin, Z.; Parham, G. H.
Hippocampus-dependent learning in SKAP-HOM deficient mice.
SKAP-HOM is an adapter protein which regulates the cross-talk between immunoreceptors and integrins and is involved in signal transduction. It is present in murine brain structures such as the hippocampus, frontal cortex, and cerebellum. In the present study we investigated types of hippocampus-dependent learning (fear conditioning, social memory, and the Morris Water Maze) and locomotor sensitization to amphetamine in transgenic SKAP-HOM deficient mice (-/-) in comparison with respective controls (+/+). Animals from both groups showed comparable fear conditioning, and the extinction of conditioned fear was accelerated in -/-. In terms of sociability, there were no differences between the animals, but in -/- mice social memory was impaired. There was no difference between the two groups of mice in spatial learning and memory measured in the Morris Water Maze. Wild-type and deficient animals exhibited similar sensitization to amphetamine. In reaction to amphetamine challenge, the response in +/+ was enhanced. It was hypothesized that SKAP-HOM deficiency does not affect hippocampus-dependent learning in general, but that its effects on cognitive tasks seem to be dependent on the nature of the cognitive task, i.e. spatial vs. non-spatial. PMID:24815314
Fiedler, Anna; Grecksch, Gisela; Reinhold, Annegret; Schraven, Burkhart; Becker, Axel
Long-term memory traces for language sounds are highly context-sensitive: an MEG/ERF study
DEFF Research Database (Denmark)
Introduction: An early component of the auditory event-related potential (ERP), the mismatch negativity (MMN), has been shown to be sensitive to native phonemic language sound contrasts compared to non-native or allophonic language sound contrasts. So far this has not been attested for different phonetic contexts. In the present study we investigated the mismatch field (MMF) response (the magnetic counterpart of the MMN) of native Danish speakers to the Danish phonetic contrast of [t]-[d] in two different phonetic contexts: One in which the sound contrast was phonemic ([tæ] versus [dæ]), and one in which the sound contrast was allophonic ([æt] versus [æd]), i.e. its phonemic status was neutralized. Methods: The stimuli consisted of the four Danish syllables: [tæ] and [dæ] (meaning �??take�?? and �??then�??, respectively), and [æt] and [æd] (both meaning �??that�??). These were presented in a passive listening MMN paradigm while participants�?? MEG was recorded. [tæ] and [æt] acted as standards, and [dæ] and [æd] thus as deviants, respectively. Results: Comparing brain responses to the deviants and the standards, only the phonemic [tæ]-[dæ] contrast showed significant effects (FWE-corrected at p<0.05 at the cluster-level) within the typical MMN time range (100 to 300 ms after deviance onset) and over both hemispheres. Comparing the differences between the two contrasts ([dæ]-[tæ] minus [æd]-[æt]), the phonemic context elicited significantly larger MMF responses than the allophonic context (FWE-corrected at p<0.05 at the cluster-level), again over both hemispheres and within the typical MMN time range. Conclusion: By manipulating the immediate phonetic context in an oddball paradigm, we demonstrate that the human brain�??s MMF response to language sounds is highly context-sensitive. This has important impact on the proposed long-term memory traces for native phonological categories. In order to generate different MMF responses to the same language sound contrast depending on the phonetic context, these long-term memory traces must thus be context-sensitive themselves or exist as separate traces for the context-dependent allophones of the phonological categories.
Nielsen, Andreas Højlund; Gebauer, Line
Very long-term memories may be stored in the pattern of holes in the perineuronal net.
A hypothesis and the experiments to test it propose that very long-term memories, such as fear conditioning, are stored as the pattern of holes in the perineuronal net (PNN), a specialized ECM that envelops mature neurons and restricts synapse formation. The 3D intertwining of PNN and synapses would be imaged by serial-section EM. Lifetimes of PNN vs. intrasynaptic components would be compared with pulse-chase (15)N labeling in mice and (14)C content in human cadaver brains. Genetically encoded indicators and antineoepitope antibodies should improve spatial and temporal resolution of the in vivo activity of proteases that locally erode PNN. Further techniques suggested include genetic KOs, better pharmacological inhibitors, and a genetically encoded snapshot reporter, which will capture the pattern of activity throughout a large ensemble of neurons at a time precisely defined by the triggering illumination, drive expression of effector genes to mark those cells, and allow selective excitation, inhibition, or ablation to test their functional importance. The snapshot reporter should enable more precise inhibition or potentiation of PNN erosion to compare with behavioral consequences. Finally, biosynthesis of PNN components and proteases would be imaged. PMID:23832785
Tsien, Roger Y
X11beta rescues memory and long-term potentiation deficits in Alzheimer's disease APPswe Tg2576 mice.
LENUS (Irish Health Repository)
Increased production and deposition of amyloid beta-protein (Abeta) are believed to be key pathogenic events in Alzheimer\\'s disease. As such, routes for lowering cerebral Abeta levels represent potential therapeutic targets for Alzheimer\\'s disease. X11beta is a neuronal adaptor protein that binds to the intracellular domain of the amyloid precursor protein (APP). Overexpression of X11beta inhibits Abeta production in a number of experimental systems. However, whether these changes to APP processing and Abeta production induced by X11beta overexpression also induce beneficial effects to memory and synaptic plasticity are not known. We report here that X11beta-mediated reduction in cerebral Abeta is associated with normalization of both cognition and in vivo long-term potentiation in aged APPswe Tg2576 transgenic mice that model the amyloid pathology of Alzheimer\\'s disease. Overexpression of X11beta itself has no detectable adverse effects upon mouse behaviour. These findings support the notion that modulation of X11beta function represents a therapeutic target for Abeta-mediated neuronal dysfunction in Alzheimer\\'s disease.
Mitchell, Jacqueline C
Making the Case that Episodic Recollection is Attributable to Operations Occurring at Retrieval rather than to Content Stored in a Dedicated Subsystem of Long-Term Memory
Directory of Open Access Journals (Sweden)
Full Text Available Episodic memory often is conceptualized as a uniquely human system of long-term memory that makes available knowledge accompanied by the temporal and spatial context in which that knowledge was acquired. Retrieval from episodic memory entails a form of first�person subjectivity called autonoetic consciousness that provides a sense that a recollection was something that took place in the experiencer�s personal past. In this paper I expand on this definition of episodic memory. Specifically, I suggest that (a the core features assumed unique to episodic memory are shared by semantic memory, (b episodic memory cannot be fully understood unless one appreciates that episodic recollection requires the coordinated function of a number of distinct, yet interacting, �enabling� systems. Although these systems � ownership, self, subjective temporality, and agency � are not traditionally viewed as memorial in nature, each is necessary for episodic recollection and jointly they may be sufficient, and (c the type of subjective awareness provided by episodic recollection (autonoetic is relational rather than intrinsic � i.e., it can be lost in certain patient populations, thus rendering episodic memory content indistinguishable from the content of semantic long-term memory.
Measuring workload differences between short-term memory and long-term memory scenarios in a simulated flight environment
Four highly experienced Air Force pilots each flew four simulated flight scenarios. Two scenarios required a great deal of aircraft maneuvering. The other two scenarios involved less maneuvering, but required remembering a number of items. All scenarios were designed to be equaly challenging. Pilot's Subjective Ratings for Activity-level, Complexity, Difficulty, Stress, and Workload were higher for the manuevering scenarios than the memory scenarios. At a moderate workload level, keeping the pilots active resulted in better aircraft control. When required to monitor and remember items, aircraft control tended to decrease. Pilots tended to weigh information about the spatial positioning and performance of their aircraft more heavily than other items.
Berg, S. L.; Sheridan, T. B.
One week of motor adaptation induces structural changes in primary motor cortex that predict long-term memory one year later
Digital Repository Infrastructure Vision for European Research (DRIVER)
The neural bases of motor adaptation have been extensively explored in human and non-human primates. A network including the cerebellum, primary motor and the posterior parietal cortex appears to be crucial for this type of learning. Yet, to date, it is unclear whether these regions contribute directly or indirectly to the formation of motor memories. Here we trained subjects on a complex visuomotor rotation associated with long-term memory (in the order of months) to identify potential sites...
Landi, Sofia M.; Baguear, Federico; Della-maggiore, Valeria
Naringin Enhances CaMKII Activity and Improves Long-Term Memory in a Mouse Model of Alzheimer�s Disease
Directory of Open Access Journals (Sweden)
Full Text Available The Amyloid-? (A?-induced impairment of hippocampal synaptic plasticity is an underlying mechanism of memory loss in the early stages of Alzheimer's disease (AD in human and mouse models. The inhibition of the calcium/calmodulin-dependent protein kinase II (CaMKII autophosphorylation plays an important role in long-term memory. In this study, we isolated naringin from Pomelo peel (a Citrus species and studied its effect on long-term memory in the APPswe/PS1dE9 transgenic mouse model of AD. Three-month-old APPswe/PS1dE9 transgenic mice were randomly assigned to a vehicle group, two naringin (either 50 or 100 mg/kg body weight/day groups, or an Aricept (2 mg/kg body weight/day group. After 16 weeks of treatment, we observed that treatment with naringin (100 mg/kg body weight/day enhanced the autophosphorylation of CaMKII, increased the phosphorylation of the ?-amino-3-hydroxy-5-methyl-4-isoxazolepropionic (AMPA receptor at a CaMKII-dependent site and improved long-term learning and memory ability. These findings suggest that the increase in CaMKII activity may be one of the mechanisms by which naringin improves long-term cognitive function in the APPswe/PS1dE9 transgenic mouse model of AD.
Lian-Feng Zhang
PKA Increases in the Olfactory Bulb Act as Unconditioned Stimuli and Provide Evidence for Parallel Memory Systems: Pairing Odor with Increased PKA Creates Intermediate- and Long-Term, but Not Short-Term, Memories
Neonatal odor-preference memory in rat pups is a well-defined associative mammalian memory model dependent on cAMP. Previous work from this laboratory demonstrates three phases of neonatal odor-preference memory: short-term (translation-independent), intermediate-term (translation-dependent), and long-term (transcription- and�
Grimes, Matthew T.; Harley, Carolyn W.; Darby-King, Andrea; McLean, John H.
The effect of zinc supplementation of lactating rats on short-term and long-term memory of their male offspring.
Background: In this study the effect of zinc chloride (ZnCl2) administration on the short-term and long-term memory of rats were assessed. Methods: We enrolled six groups of adult female and control group of eight Wistar rats in each group. One group was control group with free access to food and water, and five groups drunk zinc chloride in different doses (20, 30, 50, 70 and 100 mg/kg/day) in drinking water for two weeks during lactation .One month after birth, a shuttle box used to short- term and long-term memory and the latency in entering the dark chamber as well. Results: This experiment showed that maternal 70 mg/kg dietary zinc during lactation influenced the working memory of rats' offspring in all groups. Rats received 100 mg/kg/day zinc during lactation so they had significant impairment in working memory (short-term) of their offspring (P<0.05). There was no significant difference in reference (long-term) memory of all groups. Conclusion: Drug consumption below70 mg/kg/day zinc chloride during lactation had no effect. While enhanced 100 mg/ kg/ day zinc in lactating rats could cause short-term memory impairment. PMID:24688973
Karami, Mohammad; Ehsanivostacolaee, Simin; Moazedi, Ali Ahmad; Nosrati, Anahita
Kaolin-induced ventriculomegaly at weaning produces long-term learning, memory, and motor deficits in rats.
Ventriculomegaly occurs when there is imbalance between creation and absorption of cerebrospinal fluid (CSF); even when treated, long-term behavioral changes occur. Kaolin injection in the cisterna magna of rats produces an obstruction of CSF outflow and models one type of hydrocephalus. Previous research with this model shows that neonatal onset has mixed effects on Morris water maze (MWM) and motoric performance; we hypothesized that this might be because the severity of ventricular enlargement was not taken into consideration. In the present experiment, rats were injected with kaolin or saline on postnatal day (P)21 and analyzed in subgroups based on Evan's ratios (ERs) of the severity of ventricular enlargement at the end of testing to create 4 subgroups from least to most severe: ER0.4-0.5, ER0.51-0.6, ER0.61-0.7, and ER0.71-0.82, respectively. Locomotor activity (dry land and swimming), acoustic startle with prepulse inhibition (PPI), and MWM performance were tested starting on P28 (122cm maze) and again on P42 (244cm maze). Kaolin-treated animals weighed significantly less than controls at all times. Differences in locomotor activity were seen at P42 but not P28. On P28 there was an increase in PPI for all but the least severe kaolin-treated group, but no difference at P42 compared with controls. In the MWM at P28, all kaolin-treated groups had longer path lengths than controls, but comparable swim speeds. With the exception of the least severe group, probe trial performance was worse in the kaolin-treated animals. On P42, only the most severely affected kaolin-treated group showed deficits compared with control animals. This group showed no MWM learning and no memory for the platform position during probe trial testing. Swim speed was unaffected, indicating motor deficits were not responsible for impaired learning and memory. These findings indicate that kaolin-induced ventriculomegaly in rats interferes with cognition regardless of the final enlargement of the cerebral ventricles, but final size critically determines whether lasting locomotor, learning, and memory impairments occur. PMID:24594360
Williams, Michael T; Braun, Amanda A; Amos-Kroohs, Robyn M; McAllister, James P; Lindquist, Diana M; Mangano, Francesco T; Vorhees, Charles V; Yuan, Weihong
Long-term memory-based control of attention in multi-step tasks requires working memory: evidence from domain-specific interference
Evidence for long-term memory (LTM)-based control of attention has been found during the execution of highly practiced multi-step tasks. However, does LTM directly control for attention or are working memory (WM) processes involved? In the present study, this question was investigated with a dual-task paradigm. Participants executed either a highly practiced visuospatial sensorimotor task (speed stacking) or a verbal task (high-speed poem reciting), while maintaining visuospatial or verbal information in WM. Results revealed unidirectional and domain-specific interference. Neither speed stacking nor high-speed poem reciting was influenced by WM retention. Stacking disrupted the retention of visuospatial locations, but did not modify memory performance of verbal material (letters). Reciting reduced the retention of verbal material substantially whereas it affected the memory performance of visuospatial locations to a smaller degree. We suggest that the selection of task-relevant information from LTM for the execution of overlearned multi-step tasks recruits domain-specific WM.
Foerster, Rebecca M.; Carbone, Elena; Schneider, Werner X.
Long-term memory-based control of attention in multi-step tasks requires working memory: Evidence from domain-specific interference
Directory of Open Access Journals (Sweden)
Full Text Available Evidence for long-term memory (LTM-based control of attention has been found during the execution of highly practiced multi-step tasks. However, does LTM directly control for attention or are working memory (WM processes involved? In the present study, this question was investigated with a dual-task paradigm. Participants executed either a highly practiced visuospatial sensorimotor task (speed stacking or a verbal task (high-speed poem reciting, while maintaining visuospatial or verbal information in WM. Results revealed unidirectional and domain-specific interference. Neither speed stacking nor high-speed poem reciting was influenced by WM retention. Stacking disrupted the retention of visuospatial locations, but did not modify memory performance of verbal material (letters. Reciting reduced the retention of verbal material substantially whereas it affected the memory performance of visuospatial locations to a smaller degree. We suggest that the selection of task-relevant information from LTM for the execution of overlearned multi-step tasks recruits domain-specific WM.
Lidocaine Injections Targeting CA3 Hippocampus Impair Long-Term Spatial Memory and Prevent Learning-Induced Mossy Fiber Remodeling
Learning a spatial location induces remodeling of the mossy fiber terminal field (MFTF) in the CA3 subfield of the dorsal hippocampus (Holahan et al., 2006; Ramirez-Amaya et al., 2001; Rekart et al., 2007a). These fibers appear to grow from the stratum lucidum (SL) into distal stratum oriens (dSO). Is this axonal growth dependent on �repeated and persistent� neural activity in the CA3 region during training? To address this issue, we targeted local inactivation of the MFTF region in a post-training, consolidation paradigm. Male Wistar rats, bilaterally implanted with chronic indwelling cannulae aimed at the MFTF CA3 region, were trained on a hidden platform water maze task (10 trials per day for 5 days). Immediately after the 10th trial on each training day, rats were injected with lidocaine (4% w/V; 171 mM; n = 7) or phosphate-buffered saline (PBS; n = 7). Behavioral measures of latency, path length and thigmotaxis were recorded, as was directional heading. A retention test (probe trial) was given 7 days after the last training day and brains were subsequently processed for MFTF distribution (Timm�s stain) and cannula location. Lidocaine treatment was found to block the learning-associated structural remodeling of the MFTF that was reported previously and observed in the PBS-injected controls. During training, the lidocaine group showed elevated latencies and a misdirected heading to locate the platform on the first trial of each training day. On the 7-day retention probe trial, the lidocaine-injected group showed poor retention indicated by the absence of a search bias in the area where the platform had been located during training. These data suggest that reduction of neuronal activity in the CA3 region impairs long-term storage of spatial information. As this was associated with reduced MFTF structural remodeling, it provides initial anatomical and behavioral evidence for an activity � dependent, presynaptic growth model of memory.
Holahan, Matthew R.; Routtenberg, Aryeh
NMDA receptors and L-type voltage-gated calcium channels contribute to long-term potentiation and different components of fear memory formation in the lateral amygdala.
Long-term potentiation (LTP) at sensory input synapses to the lateral amygdala (LA) is a candidate mechanism for memory storage during fear conditioning. We evaluated the effect of L-type voltage-gated calcium channel (VGCC) and NMDA receptor (NMDAR) blockade in LA on LTP at thalamic input synapses induced by two different protocols in vitro and on fear memory in vivo. When induced in vitro by pairing weak presynaptic stimulation with strong (spike eliciting) postsynaptic depolarization, LTP was dependent on VGCCs and not on NMDARs, but, when induced by a form of tetanic stimulation that produced prolonged postsynaptic depolarization (but not spikes), LTP was dependent on NMDARs and not on VGCCs. In behavioral studies, bilateral infusions of NMDAR antagonists into the LA impaired both short-term and long-term memory of fear conditioning, whereas VGCC blockade selectively impaired long-term memory formation. Collectively, the results suggest that two pharmacologically distinct forms of LTP can be isolated in the LA in vitro and that a combination of both contribute to the formation of fear memories in vivo at the cellular level. PMID:12077219
Bauer, Elizabeth P; Schafe, Glenn E; LeDoux, Joseph E
Selective suppression of hippocampal ripples impairs spatial memory.
Sharp wave-ripple (SPW-R) complexes in the hippocampus-entorhinal cortex are believed to be important for transferring labile memories from the hippocampus to the neocortex for long-term storage. We found that selective elimination of SPW-Rs during post-training consolidation periods resulted in performance impairment in rats trained on a hippocampus-dependent spatial memory task. Our results provide evidence for a prominent role of hippocampal SPW-Rs in memory consolidation. PMID:19749750
Girardeau, Gabrielle; Benchenane, Karim; Wiener, Sidney I; Buzs�ki, Gy�rgy; Zugaro, Micha�l B
Inhibition of the interactions between eukaryotic initiation factors 4E and 4G impairs long-term associative memory consolidation but not reconsolidation
Digital Repository Infrastructure Vision for European Research (DRIVER)
Considerable evidence indicates that the general blockade of protein synthesis prevents both the initial consolidation and the postretrieval reconsolidation of long-term memories. These findings come largely from studies of drugs that block ribosomal function, so as to globally interfere with both cap-dependent and -independent forms of translation. Here we show that intra-amygdala microinfusions of 4EGI-1, a small molecule inhibitor of cap-dependent translation that selectively disrupts the ...
Improvement in Memory and Brain Long-term Potentiation Deficits Due to Permanent Hypoperfusion/Ischemia by Grape Seed Extract in Rats.
Objective(s): Cerebral hypoperfusion/ischemia (CHI) is a neurological disease where impaired hippocampus electrical activity and cognition caused by a serial pathophysiological events. This study aimed to evaluate the effects of chronic oral administration of grape seed extract (GSE) on passive avoidance memory and long-term potentiation (LTP) after permanent bilateral common carotid arteries occlusion (2CCAO) in male adult rats. Materials and Methods: Thirty-two adult male Wistar rats were randomly divided into: 1) Sham+Veh, 2) Isch+Veh, 3) Sham+GSE, 4) Isch+GSE. In order to make 2CCAO as an animal model of CHI, carotid arteries were ligatured and then cut bilaterally. To evaluation of passive avoidance memory, step-down latency (STL) was measured and LTP was recorded from hippocampal dentate gyrus (DG) after high frequency stimulation (HFS) in all rats. Results: We found that memory was significantly impaired in rats after CHI (P<0.001) concomitant with hippocampal LTP inhibition (P<0.05, P<0.01 for LTP1 and LTP48 respectively). GSE treatment significantly improved memory impairment and increased hippocampal LTP in rats with 2CCAO. Conclusion: Our results in present study suggest that GSE exhibits therapeutic potential for short-and long-term memories as well as LTP in DG, which is most likely related at least in part to its antioxidative and free radical scavenging actions. PMID:24171080
Sarkaki, Alireza; Rafieirad, Maryam; Hossini, Seyed Ebrahim; Farbood, Yaghoub; Motamedi, Fereshteh; Mansouri, Seyed Mohammad Taghi; Naghizadeh, Bahareh
Spatial cognition and memory: a reversible lesion with lidocaine into the anteromedial/posterior parietal cortex (AM/PPC affects differently working and long-term memory on two foraging tasks
Directory of Open Access Journals (Sweden)
Full Text Available Place memory is relevant for exploration and forage behaviour. When food supply is dispersed, a win-shift has advantage over a win-stay strategy. In the Olton Octagonal Maze, the rat follows a win-shift strategy using working memory. However, in the Olton 4x4 version, the rat follows a win-stay strategy, using both working and long-term memories. It has been suggested that the neocortex is required for the resolution of tasks demanding long-term, but not for that demanding working memory alone. The role of anteromedial/posterior parietal cortex (AM/PPC was investigated here, using a reversible lesion induced by intracerebral lidocaine infusion. Long-Evans rats were implanted with guide cannulae into the AM/PPC and trained in an Olton 4x4 maze, counting working and long-term memory errors after a delay. Then, the animals were infused with lidocaine or saline during the delay phase and tested for three days. Another series of animals, treated as before, was tested in an Olton Octagonal Maze and subjected to the same injection schedule. In the Olton 4x4 Maze, lidocaine produced a significant increase in working and long-term memory errors, compared to saline and post-lidocaine conditions. In contrast, in the Olton Octagonal Maze, lidocaine did not induce any effect on working memory errors. Thus, AM/PPC is required when both working with previous information and long-term memories are needed, but not when only working memory is required, as it happens under ethological conditions. Whenever food supply is dispersed, a win-shift strategy is preferable
Extracellular Signal-Regulated Kinase Activity in the Entorhinal Cortex Is Necessary for Long-Term Spatial Memory
Digital Repository Infrastructure Vision for European Research (DRIVER)
Lesion studies have provided evidence that the entorhinal cortex (EC) participates in spatial memory. However, the molecular cascades that underlie memory-associated changes in the EC and its specific role in spatial memory, however, have not been clearly delineated. Recently, it has been shown that activation of extracellular signal-regulated kinase (Erk, a mitogen-activated protein kinase family member) in the dorsal hippocampus is necessary for spatial memory. To examine whether similar me...
Hebert, April E.; Dash, Pramod K.
Relevance of synaptic tagging and capture to the persistence of long-term potentiation and everyday spatial memory
Digital Repository Infrastructure Vision for European Research (DRIVER)
Memory for inconsequential events fades, unless these happen before or after other novel or surprising events. However, our understanding of the neurobiological mechanisms of novelty-enhanced memory persistence is mainly restricted to aversive or fear-associated memories. We now outline an �everyday appetitive� behavioral model to examine whether and how unrelated novelty facilitates the persistence of spatial memory coupled to parallel electrophysiological studies of the persistence of l...
Wang, Szu-han; Redondo, Roger L.; Morris, Richard G. M.
Maternal Diabetes in Pregnancy: Early and Long-Term Outcomes on the Offspring and the Concept of �Metabolic Memory�
Digital Repository Infrastructure Vision for European Research (DRIVER)
The adverse outcomes on the offspring from maternal diabetes in pregnancy are substantially documented. In this paper, we report main knowledge on impacts of maternal diabetes on early and long-term health of the offspring, with specific comments on maternal obesity. The main adverse outcome on progenies from pregnancy complicated with maternal diabetes appears to be macrosomia, as it is commonly known that intrauterine exposure to hyperglycemia increases the risk and programs the offspring t...
Yessoufou, Akadiri; Moutairou, Kabirou
Maternal separation impairs long term-potentiation in CA1-CA3 synapses and hippocampal-dependent memory in old rats.
Exposure to chronic stress during the neonatal period is known to induce permanent long-term changes in the central nervous system and hipothalamic-pituitary-adrenal axis reactivity that are associated with increased levels of depression, anxiety, and cognitive impairments. In rodents, a validated model of early life stress is the maternal separation (MS) paradigm, which has been shown to have long-term consequences for the pups that span to adulthood. We hypothesized that the early life stress-associated effects could be exacerbated with aging, because it is often accompanied by cognitive decline. Using a MS model in which rat pups were separated from their mothers for 3 hours daily, during postnatal days 2-14, we evaluated the long-term functional consequences to aged animals (70-week-old), by measuring synaptic plasticity and cognitive performance. The baseline behavioral deficits of aged control rats were further exacerbated in MS animals, indicating that early-life stress induces sustained changes in anxiety-like behavior and hippocampal-dependent memory that are maintained much later in life. We then investigated whether these differences are linked to impaired function of hippocampal neurons by recording hippocampal long-term potentiation from Schaffer collaterals/CA1 synapses. The magnitude of the hippocampal long-term potentiation induced by high-frequency stimulation was significantly lower in aged MS animals than in age-matched controls. These results substantiate the hypothesis that the neuronal and endocrine alterations induced by early-life stress are long lasting, and are able to exacerbate the mild age-associated deficits. PMID:24559649
Sousa, Vasco C; Vital, Joana; Costenla, Ana Rita; Batalha, V�nia L; Sebasti�o, Ana M; Ribeiro, Joaquim A; Lopes, Lu�sa V
Presynaptic long-term plasticity
Directory of Open Access Journals (Sweden)
Full Text Available Long-term synaptic plasticity is a major cellular substrate for learning, memory, and behavioral adaptation. Although early examples of long-term synaptic plasticity described a mechanism by which postsynaptic signal transduction was potentiated, it is now apparent that there is a vast array of mechanisms for long-term synaptic plasticity that involve modifications to either or both the presynaptic terminal and postsynaptic site. In this article, we discuss current and evolving approaches to identify presynaptic mechanisms as well as discuss their limitations. We next provide examples of the diverse circuits in which presynaptic forms of long-term synaptic plasticity have been described and discuss the potential contribution this form of plasticity might add to circuit function. Finally, we examine the present evidence for the molecular pathways and cellular events underlying presynaptic long-term synaptic plasticity.
Long-term methionine exposure induces memory impairment on inhibitory avoidance task and alters acetylcholinesterase activity and expression in zebrafish (Danio rerio).
Hypermethioninemic patients exhibit a variable degree of neurological dysfunction. However, the mechanisms involved in these alterations have not been completely clarified. Cholinergic system has been implicated in many physiological processes, including cognitive performances, as learning, and memory. Parameters of cholinergic signaling have already been characterized in zebrafish brain. Since zebrafish is a small freshwater teleost which is a vertebrate model for modeling behavioral and functional parameters related to human pathogenesis and for clinical treatment screenings, in the present study we investigated the effects of short- and long-term methionine exposure on cognitive impairment, AChE activity and gene expression in zebrafish. For the studies, animals were exposed at two methionine concentrations (1.5 and 3.0 mM) during 1 h or 7 days (short- or long-term treatments, respectively). We observed a significant increase in AChE activity of zebrafish brain membranes after long-term methionine exposure at 3.0 mM. However, AChE gene expression decreased significantly in both concentrations tested after 7 days of treatment, suggesting that post-translational events are involved in the enhancement of AChE activity. Methionine treatment induces memory deficit in zebrafish after long-term exposure to this amino acid, which could be related, at least in part, with cognitive impairment observed in hypermethioninemia. Therefore, the results here presented raise a new perspective to use the zebrafish as a complementary vertebrate model for studying inborn errors of metabolism, which may help to better understand the pathophysiology of this disease. PMID:22437435
Vuaden, Fernanda Cenci; Savio, Luiz Eduardo B; Piato, Angelo L; Pereira, Talita C; Vianna, M�nica R; Bogo, Maur�cio R; Bonan, Carla D; Wyse, Angela T S
Genetic deletion of gadd45b, a regulator of active DNA demethylation, enhances long-term memory and synaptic plasticity
Digital Repository Infrastructure Vision for European Research (DRIVER)
Dynamic epigenetic mechanisms including histone and DNA modifications regulate animal behavior and memory. While numerous enzymes regulating these mechanisms have been linked to memory formation, the regulation of active DNA demethylation (i.e. � cytosine-5 demethylation) has only recently been investigated. New discoveries aim towards the Gadd45 family, particularly Gadd45b, in activity-dependent demethylation in the adult CNS. This study found memory-associated expression of gadd45b in th...
Sultan, Faraz A.; Wang, Jing; Tront, Jennifer; Liebermann, Dan A.; Sweatt, J. David
Forebrain NR2B Overexpression Facilitating the Prefrontal Cortex Long-Term Potentiation and Enhancing Working Memory Function in Mice
Digital Repository Infrastructure Vision for European Research (DRIVER)
Prefrontal cortex plays an important role in working memory, attention regulation and behavioral inhibition. Its functions are associated with NMDA receptors. However, there is little information regarding the roles of NMDA receptor NR2B subunit in prefrontal cortical synaptic plasticity and prefrontal cortex-related working memory. Whether the up-regulation of NR2B subunit influences prefrontal cortical synaptic plasticity and working memory is not yet clear. In the present study, we measure...
Cui, Yihui; Jin, Jing; Zhang, Xuliang; Xu, Hao; Yang, Liguo; Du, Dan; Zeng, Qingwen; Tsien, Joe Z.; Yu, Huiting; Cao, Xiaohua
Muscle tension induced after learning enhances long-term narrative and visual memory in healthy older adults.
Arousing events are better remembered than mundane events. Indeed, manipulation of arousal, such as by muscle tension, can influence memory even when it occurs shortly after learning. Indeed, our founding study showed this approach can raise delayed memory performance in older adults to a level comparable to that of unaided young adults. Yet, systematic studies, especially those investigating different modalities or types of memory, have not been done. This study investigated the effects of a brief bout of isometric exercise via handgrip on narrative and visuospatial episodic memory in healthy elders. Forty-seven participants completed the Logical Memory subtest of the Wechsler Memory Scales III (LM) and the Benton Visual Retention Test (BVRT), followed alternately by no treatment and by moderately squeezing a sand-filled latex ball for 1-min (counterbalanced order and test forms). Isometric exercise significantly increased both positive and negative affect ratings. Retention was tested 2 weeks later. Delayed recall and recognition of LM was enhanced by arousal relative to control, as was recognition of the BVRT. The results extend past findings that muscle tension induced after learning modulates memory consolidation, extending findings in elders to suggest that a simple form of isometric exercise can have practical effects, such as aiding memory for stories and images. PMID:24434768
Nielson, Kristy A; Wulff, Laura L; Arentsen, Timothy J
Long Term Recall of Memory CD8 T Cells in Mice to First and Third Generation Smallpox Vaccines
Digital Repository Infrastructure Vision for European Research (DRIVER)
Since long-term immunity is a critical component of any effective vaccine, we compared over a 15 month period, the strength, durability and specificity of immunity of an attenuated smallpox vaccine Modified Vaccinia Ankara (MVA) to the New York City Board of Health (NYCBH) vaccine. The frequencies of CD8+ T cells to an immunodominant CD8 T cell epitope B8R20�27 remained remarkably stable in mice given either MVA or NYCBH. Both groups were also protected from a lethal intranasal challenge wi...
Green, Sharone; Ennis, Francis A.; Mathew, Anuja
Dose-dependent Effects of Iron Supplementation on Short-term and Long-term Memory in Adult Male Wistar Rats
Digital Repository Infrastructure Vision for European Research (DRIVER)
The aim of the present study was to evaluate the effects of dose-dependent of iron supplementation on short-term and long-term memory in adult male rats in a shuttle box. Iron imbalance in the brain, including excess accumulation and deficiency are associated with neurological disease and dysfunction; yet, their origins are poorly understood. So, in this study were investigated the effects of iron on the behavior of adult wistar rats. Rats were treated with different doses of iron (0, 10, 20,...
Moazedi Ahmad Ali; Khombi Shooshtari Maryam; Parham Gholam Ali
CaMKII, but not protein kinase A, regulates Rpt6 phosphorylation and proteasome activity during the formation of long-term memories
Directory of Open Access Journals (Sweden)
Full Text Available CaMKII and Protein Kinase A (PKA are thought to be critical for synaptic plasticity and memory formation through their regulation of protein synthesis. Consistent with this, numerous studies have reported that CaMKII, PKA and protein synthesis are critical for long-term memory formation. Recently, we found that protein degradation through the ubiquitin-proteasome system is also critical for long-term memory formation in the amygdala. However, the mechanism by which ubiquitin-proteasome activity is regulated during memory formation and how protein degradation interacts with known intracellular signaling pathways important for learning remain unknown. Recently, evidence has emerged suggesting that both CaMKII and PKA are capable of regulating proteasome activity in vitro through the phosphorylation of proteasome regulatory subunit Rpt6 at Serine-120, though whether they regulate Rpt6 phosphorylation and proteasome function in vivo remains unknown. In the present study we demonstrate for the first time that fear conditioning transiently modifies a proteasome regulatory subunit and proteasome catalytic activity in the mammalian brain in a CaMKII-dependent manner. We found increases in the phosphorylation of proteasome ATPase subunit Rpt6 at Serine-120 and an enhancement in proteasome activity in the amygdala following fear conditioning. Pharmacological manipulation of CaMKII, but not PKA, in vivo significantly reduced both the learning-induced increase in Rpt6 Serine-120 phosphorylation and the increase in proteasome activity without directly affecting protein polyubiquitination levels. These results indicate a novel role for CaMKII in memory formation through its regulation of protein degradation and suggest that CaMKII regulates Rpt6 phosphorylation and proteasome function both in vitro and in vivo.
A spatially-supported forced-choice recognition test reveals children�s long-term memory for newly learned word forms
Directory of Open Access Journals (Sweden)
Full Text Available Children�s memories for the link between a newly trained word and its referent have been the focus of extensive past research. However, memory for the word form itself is rarely assessed among preschool-age children. When it is, children are typically asked to verbally recall the forms, and they generally perform at floor on such tests. To better measure children�s memory for word forms, we aimed to design a more sensitive test that required recognition rather than recall, provided spatial cues to off-set the phonological memory demands of the test, and allowed pointing rather than verbal responses. We taught 12 novel word-referent pairs via ostensive naming to sixteen 4-to-6-year-olds and measured their memory for the word forms after a week-long retention interval using the new spatially-supported form recognition test. We also measured their memory for the word-referent links and the generalization of the links to untrained referents with commonly used recognition tests. Children demonstrated memory for word forms at above chance levels; however, their memory for forms was poorer than their memory for trained or generalized word-referent links. When in error, children were no more likely to select a foil that was a close neighbor to the target form than a maximally different foil. Additionally, they more often selected correct forms that were among the first six than the last six to be trained. Overall, these findings suggest that children are able to remember word forms after a limited number of ostensive exposures and a long-term delay. However, word forms remain more difficult to learn than word-referent links and there is an upper limit on the number of forms that can be learned within a given period of time.
Long-Term Memory and Topographical Disorientation in Healthy Elderly People: Preliminary Results of a New Diagnostic Tool
Digital Repository Infrastructure Vision for European Research (DRIVER)
In the physiological aging, a reduction in processing speed, episodic memory and working memory has been established. However, little is known about navigational abilities in elderly people and few ecological tools are available. Recently, some evidences have suggested topographical disorientation (TD) as a possible indicator of conversion from amnesic Mild Cognitive Impairment (a-MCI) to Alzheimer�s disease (AD). Our purpose was to create and validate a new ecological instrument in healthy...
Rusconi, Maria Luisa; Zamin, Claudia; Carelli, Laura
Human dendritic cells sequentially matured with CD4+ T cells as a secondary signal favor CTL and long-term T memory cell responses
Scientific Electronic Library Online (English)
Full Text Available SciELO Chile | Language: English Abstract in english Dendritic cells (DCs) are professional antigen-presenting cells involved in the control and initiation of immune responses. In vivo, DCs exposed at the periphery to maturation stimuli migrate to lymph nodes, where they receive secondary signals from CD4+ T helper cells. These DCs become able to init [...] iate CD8+ cytotoxic T lymphocyte (CTL) responses. However, in vitro investigations concerning human monocyte-derived DCs have never focused on their functional properties after such sequential maturation. Here, we studied human DC phenotypes and functions according to this sequential exposure to maturation stimuli. As first signals, we used TNF-?/polyI:C mimicking inflammatory and pathogen stimuli and, as second signals, we compared activated CD4+ T helper cells to a combination of CD40-L/ IFN-?. Our results show that a sequential activation with activated CD4+ T cells dramatically increased the maturation of DCs in terms of their phenotype and cytokine secretion compared to DCs activated with maturation stimuli delivered simultaneously. Furthermore, this sequential maturation led to the induction of CTL with a long-term effector and central memory phenotypes. Thus, sequential delivery of maturation stimuli, which includes CD4+ T cells, should be considered in the future to improve the induction of long-term CTL memory in DC-based immunotherapy.
Simon, Thomas; Tanguy-Royer, S�verine; Royer, Pierre-Joseph; Boisgerault, Nicolas; Frikeche, Jihane; Fonteneau, Jean-Fran�ois; Gr�goire, Marc.
Human dendritic cells sequentially matured with CD4+ T cells as a secondary signal favor CTL and long-term T memory cell responses
Directory of Open Access Journals (Sweden)
Full Text Available Dendritic cells (DCs are professional antigen-presenting cells involved in the control and initiation of immune responses. In vivo, DCs exposed at the periphery to maturation stimuli migrate to lymph nodes, where they receive secondary signals from CD4+ T helper cells. These DCs become able to initiate CD8+ cytotoxic T lymphocyte (CTL responses. However, in vitro investigations concerning human monocyte-derived DCs have never focused on their functional properties after such sequential maturation. Here, we studied human DC phenotypes and functions according to this sequential exposure to maturation stimuli. As first signals, we used TNF-?/polyI:C mimicking inflammatory and pathogen stimuli and, as second signals, we compared activated CD4+ T helper cells to a combination of CD40-L/ IFN-?. Our results show that a sequential activation with activated CD4+ T cells dramatically increased the maturation of DCs in terms of their phenotype and cytokine secretion compared to DCs activated with maturation stimuli delivered simultaneously. Furthermore, this sequential maturation led to the induction of CTL with a long-term effector and central memory phenotypes. Thus, sequential delivery of maturation stimuli, which includes CD4+ T cells, should be considered in the future to improve the induction of long-term CTL memory in DC-based immunotherapy.
Thomas Simon
Differential effects of spaced vs. massed training in long-term object-identity and object-location recognition memory.
Here we tested whether the well-known superiority of spaced training over massed training is equally evident in both object identity and object location recognition memory. We trained animals with objects placed in a variable or in a fixed location to produce a location-independent object identity memory or a location-dependent object representation. The training consisted of 5 trials that occurred either on one day (Massed) or over the course of 5 consecutive days (Spaced). The memory test was done in independent groups of animals either 24h or 7 days after the last training trial. In each test the animals were exposed to either a novel object, when trained with the objects in variable locations, or to a familiar object in a novel location, when trained with objects in fixed locations. The difference in time spent exploring the changed versus the familiar objects was used as a measure of recognition memory. For the object-identity-trained animals, spaced training produced clear evidence of recognition memory after both 24h and 7 days, but massed-training animals showed it only after 24h. In contrast, for the object-location-trained animals, recognition memory was evident after both retention intervals and with both training procedures. When objects were placed in variable locations for the two types of training and the test was done with a brand-new location, only the spaced-training animals showed recognition at 24h, but surprisingly, after 7 days, animals trained using both procedures were able to recognize the change, suggesting a post-training consolidation process. We suggest that the two training procedures trigger different neural mechanisms that may differ in the two segregated streams that process object information and that may consolidate differently. PMID:23644160
Bello-Medina, Paola C; S�nchez-Carrasco, Livia; Gonz�lez-Ornelas, Nadia R; Jeffery, Kathryn J; Ram�rez-Amaya, V�ctor
Deficits in memory and hippocampal long-term potentiation in mice with reduced calbindin D28K expression.
Digital Repository Infrastructure Vision for European Research (DRIVER)
The influx of calcium into the postsynaptic neuron is likely to be an important event in memory formation. Among the mechanisms that nerve cells may use to alter the time course or size of a spike of intracellular calcium are cytosolic calcium binding or "buffering" proteins. To consider the role in memory formation of one of these proteins, calbindin D28K, which is abundant in many neurons, including the CA1 pyramidal cells of the hippocampus, transgenic mice deficient in calbindin D28K have...
Molinari, S.; Battini, R.; Ferrari, S.; Pozzi, L.; Killcross, A. S.; Robbins, T. W.; Jouvenceau, A.; Billard, J. M.; Dutar, P.; Lamour, Y.; Baker, W. A.; Cox, H.; Emson, P. C.
Effect of Oral Aluminum Chloride Administration During Lactation on Short and Long-Term Memory of Their Offspring
Digital Repository Infrastructure Vision for European Research (DRIVER)
To study the relationship between aluminum chloride (AlCl3) and memory of their offspring male. Five groups of adult Wistar rats (200 � 30) were taken for this experiment. Female rats were concurrently exposed (0, 200, 400, 600 and 800 mg/kg/day) of aluminum administered as AlCl3 in drinking water for two weeks. Forty-five after birth, a shuttle box was used to test memory. This experiment showed that maternal dietary exposure Alcl3 (200, 400 and 600 m...
Moazedi Ahmad Ali; Ehsani Vostacolaee Simin; Chinipardaz Rahim
The effect of long term administration of ascorbic acid on the learning and memory deficits induced by diabetes in rat
Directory of Open Access Journals (Sweden)
Full Text Available "n Normal 0 false false false EN-US X-NONE AR-SA MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:Arial; mso-bidi-theme-font:minor-bidi;} Background: Ascorbic acid improves cognitive impairments in several experimental models. Diabetes causes learning and memory deficits. In this study we hypothesized that chronic treatment with ascorbic acid (100mg/kg, p.o would affect on the passive avoidance learning (PAL and memory in control and streptozocin-induced diabetic rats."n"nMethods: Diabetes was induced by a single i.p. injection of STZ (60mg/kg. The rats were considered diabetic if plasma glucose levels exceeded 250mg/dl on three days after STZ injection. Treatment was begun at the onset of hyperglycemia. PAL was assessed 30 days later. Retention test was done 24 h after training. At the end, animals were weighted and blood samples were drawn for plasma glucose measurement."n"nResults: Diabetes caused impairment in acquisition and retrieval processes of PAL and memory in rats. Ascorbic acid treatment improved learning and memory in control rats and reversed learning and memory deficits in diabetic rats. Ascorbic acid administration also improved the body weight loss and hyperglycemia of diabetics. Hypoglycemic and antioxidant properties of the vitamin may be involved in the memory improving effects of such treatment."n"nConclusion: These results show that ascorbic acid administration to rats for 30 days from onset of diabetes alleviated the negative influence of diabetes on learning and memory. Comparing with other nootropic drugs, vitamins have fewer side effects. Therefore, this regimen may provide a new potential alternative for prevention of the impaired cognitive functions associated with diabetes after confirming by clinical trials.
Parisa Hasanein
Long-term moderate elevation of corticosterone facilitates avian food-caching behaviour and enhances spatial memory.
Digital Repository Infrastructure Vision for European Research (DRIVER)
It is widely assumed that chronic stress and corresponding chronic elevations of glucocorticoid levels have deleterious effects on animals' brain functions such as learning and memory. Some animals, however, appear to maintain moderately elevated levels of glucocorticoids over long periods of time under natural energetically demanding conditions, and it is not clear whether such chronic but moderate elevations may be adaptive. I implanted wild-caught food-caching mountain chickadees (Poecile ...
Pravosudov, Vladimir V.
Technical Note: Long-term memory effect in the atmospheric CO2 concentration at Mauna Loa
Digital Repository Infrastructure Vision for European Research (DRIVER)
The monthly mean values of the atmospheric carbon dioxide concentration derived from in-situ air samples collected at Mauna Loa Observatory, Hawaii, USA during 1958�2004 (the longest continuous record available in the world) are analyzed by employing the detrended fluctuation analysis to detect scaling behavior in this time series. The main result is that the fluctuations of carbon dioxide concentrations exhibit long-range power-law correlations (long memory) with lag times ranging from...
Varotsos, C.; -n Assimakopoulos, M.; Efstathiou, M.
Technical Note: Long-term memory effect in the atmospheric CO2 concentration at Mauna Loa
Digital Repository Infrastructure Vision for European Research (DRIVER)
The monthly mean values of the atmospheric carbon dioxide concentration derived from in-situ air samples collected at Mauna Loa Observatory, Hawaii, during 1958�2004 (the longest continuous record available in the world) are analyzed by employing the detrended fluctuation analysis to detect scaling behavior in this time series. The main result is that the fluctuations of carbon dioxide concentrations exhibit long-range power-law correlations (long memory) with lag times ranging from fou...
Varotsos, C.; -n Assimakopoulos, M.; Efstathiou, M.
Long-term expansion of effector/memory V?2? ?? T cells is a specific blood signature of CMV infection
Digital Repository Infrastructure Vision for European Research (DRIVER)
The ability of human ?? T cells to develop immunologic memory is still a matter of debate. We previously demonstrated the involvement of V?2? ?? T lymphocytes in the response of immunosuppressed organ recipients to cytomegalovirus (CMV). Here, we demonstrate their ability to mount an adaptive immune response to CMV in immunocompetent subjects. V?2? ?? T-cell peripheral blood numbers, repertoire restriction, and cytotoxicity against CMV-infected fibroblasts were markedly increased ...
Pitard, Vincent; Roumanes, David; Lafarge, Xavier; Couzi, Lionel; Garrigue, Isabelle; Lafon, Marie-edith; Merville, Pierre; Moreau, Jean-franc?ois; De?chanet-merville, Julie
Long-term administration of ginsenoside Rh1 enhances learning and memory by promoting cell survival in the mouse hippocampus.
Ginsenosides, the secondary plant metabolites produced by Panax ginseng are responsible for the enhancing effects on learning observed following treatment with Panax ginseng. A number of studies have provided correlational evidence that cell proliferation and survival are closely associated with hippocampal-dependent learning tasks. In this study, to investigate the beneficial effects of ginsenoside Rh1 on hippocampal cells and learning, mice (6 months old) were administered ginsenoside Rh1 at a dose of 5 and 10 mg/kg/day for a period of 3 months. Saline-treated mice were used as controls. The enhancement of memory and learning in the mice was evaluated by hippocampal-dependent tasks (passive avoidance tests and Morris water maze tests) and the immunohistochemical marker of cell proliferation, bromodeoxyuridine (BrdU). In addition, the levels of brain-derived neurotrophic factor (BDNF) were measured following treatment. Based on our data, the Rh1-treated group (5 and 10 mg/kg) showed a significantly improved learning and memory ability in the passive avoidance tests compared with the control group; however, only treatment with 10 mg/kg ginsenoside Rh1 significantly promoted spatial learning ability in the Morris water maze test. Ginsenoside Rh1 significantly enhanced cell survival in the dentate gyrus of mice, although it did not enhance hippocampal cell proliferation. In addition, ginsenoside Rh1 upregulated the expression of BDNF. These findings address the potential therapeutic significance of ginsenoside Rh1 as a nutritional supplement in memory loss and neurodegenerative diseases. PMID:24212564
Hou, Jingang; Xue, Jianjie; Lee, Mira; Yu, Jiaojiao; Sung, Changkeun
Enhancement of long-term memory retention and short-term synaptic plasticity in cbl-b null mice
Digital Repository Infrastructure Vision for European Research (DRIVER)
The cbl-b gene is a member of the cbl protooncogene family. It encodes a protein with multiple domains, which can interact with other proteins in a variety of signaling pathways. The functions of cbl family genes in the brain are unknown. In this report, we used genetic, immunohistochemical, behavioral, and electrophysiological approaches to study the role of cbl-b in learning and memory. Cbl-b null mice developed normally and had no abnormalities in their locomotor performance. In spatial le...
Tan, Dong Ping; Liu, Qi-ying; Koshiya, Naohiro; Gu, Hua; Alkon, Daniel
Dose-dependent Effects of Iron Supplementation on Short-term and Long-term Memory in Adult Male Wistar Rats
Directory of Open Access Journals (Sweden)
Full Text Available The aim of the present study was to evaluate the effects of dose-dependent of iron supplementation on short-term and long-term memory in adult male rats in a shuttle box. Iron imbalance in the brain, including excess accumulation and deficiency are associated with neurological disease and dysfunction; yet, their origins are poorly understood. So, in this study were investigated the effects of iron on the behavior of adult wistar rats. Rats were treated with different doses of iron (0, 10, 20, 30, 50, 70, 100, 120, 150 mg kg-1 by gavage for 3 consecutive days and the effects of iron supplementation on passive avoidance memory were studied by shuttle box. The results showed that iron supplementation (20, 30 mg kg-1 significantly (p-1 significantly (p-1 impairment (p<0.05 short term memory. Thus, we can assume that the organism, particularly the adults, can compensate for a small dose of iron supplementation and there exists a mechanism that certainly protects the brain against iron overload until a certain point but cannot compensate for when the load exceeds this limit.
Parham Gholam Ali
The n-butanolic extract of Opuntia ficus-indica var. saboten enhances long-term memory in the passive avoidance task in mice.
Opuntia ficus-indica var. saboten Makino (Cactaceae) is used to treat burns, edema, dyspepsia, and asthma in traditional medicine. The present study investigated the beneficial effects of the n-butanolic extract of O. ficus-indica var. saboten (BOF) on memory performance in mice and attempts to uncover the mechanisms underlying its action. Memory performance was assessed with the passive avoidance task, and western blotting and immunohistochemistry were used to measure changes in protein expression and cell survival. After the oral administration of BOF for 7 days, the latency time in the passive avoidance task was significantly increased relative to vehicle-treated controls (P<0.05). Western blotting revealed that the expression levels of brain-derived neurotrophic factor (BDNF), phosphorylated cAMP response element binding-protein (pCREB), and phosphorylated extracellular signal-regulated kinase (pERK) 1/2 were significantly increased in hippocampal tissue after 7 days of BOF administration (P<0.05). Doublecortin and 5-bromo-2-deoxyuridine immunostaining also revealed that BOF significantly enhanced the survival of immature neurons, but did not affect neuronal cell proliferation in the subgranular zone of the hippocampal dentate gyrus. These results suggest that the subchronic administration of BOF enhances long-term memory, and that this effect is partially mediated by ERK-CREB-BDNF signaling and the survival of immature neurons. PMID:20493231
Kim, Jong Min; Kim, Dong Hyun; Park, Se Jin; Park, Dong Hyun; Jung, Seo Yun; Kim, Hyoung Ja; Lee, Yong Sup; Jin, Changbae; Ryu, Jong Hoon
Long-term exposure to low frequency electro-magnetic fields of 50- and 217-Hz leads to learning and memory deficits in mice
Directory of Open Access Journals (Sweden)
Full Text Available Electromagnetic field (EMF radiation affects cellular and brain chemistry and function, resulting in deleterious effects such as free radicals formation, impaired DNA repair, reduced melatonin and blood brain barrier protection, and defects on learning and memory and other higher brain functions. In this paper the effects of low frequency EMF of 50- and 217 Hz, ranges often associated with common electronic devices such as televisions and cell phones were examined on learning and memory in adult male mice. Five groups (n=10 mice/group of mice (1 control and 4 experimental were initially trained for the passive avoidance (PA test. They were then placed in devices creating EMF radiation with varying intensities (0.5 to 2 milli-Tesla, mT and frequencies (50- and 217-Hz for 2-weeks (16 hrs/day. Control mice received no radiation. Learning and memory was tested by the PA test and evaluated based on the following parameters: mean step through latency (STL, number of crossing (Cr# and time in dark compartment (TDC. Results showed significant deficiencies in learning and memory in the EM-exposed mice compared to controls: mean STL decreased significantly (p<0.001 in the 50 Hz group (1 and 1.5 mT intensities. In the 217 Hz group, STL also decreased in the 0.5 and 2 mT groups (p< 0.05. There was a notable increase in mean Cr# for both groups and TDC for 50 Hz group. Results confirm that long-term exposure to EMF radiation of 50 and 217 Hz, imparts significant harmful changes on memory and learning, reiterating the need for preventive measures against such exposures.
Soheila Khodakarim
Neural cell adhesion molecules, CaM kinase II and long-term memory in the chick.
The intermediate and medial hyperstriatum ventrale (IMHV) of the chick brain is a site of recognition memory for filial imprinting. Previous results have demonstrated learning-related changes in the amounts of the three major isoforms of neural cell adhesion molecule (NCAM) in the left IMHV. The increases were present 24 h after training. The present study enquired whether the increases persisted and were present 48 h after training. The brain regions analysed were the left and right IMHV and the left and right hyperstriatum accessorium (HA), a visual projection area. The alpha-subunit of calcium/calmodulin protein kinase II (CaMKIIalpha) was also assayed. There were significant correlations between a measure of the strength of learning and the amount of NCAM 180 in the right IMHV (r = +0.65; p = 0.012) but not in the left, and in the left HA (r = -0.61; p = 0.02), but not in the right. There were no learning-related changes for CaMKIIalpha. We conclude that in IMHV the effects of imprinting on NCAM 180 are expressed mainly in the left IMHV 24 h after training, but 48 h after training are expressed mainly in the right IMHV. PMID:11043538
Solomonia, R O; Kiguradze, T; McCabe, B J; Horn, G
One week of motor adaptation induces structural changes in primary motor cortex that predict long-term memory one year later.
The neural bases of motor adaptation have been extensively explored in human and nonhuman primates. A network including the cerebellum, primary motor cortex, and posterior parietal cortex appears to be crucial for this type of learning. Yet, to date, it is unclear whether these regions contribute directly or indirectly to the formation of motor memories. Here we trained subjects on a complex visuomotor rotation associated with long-term memory (in the order of months) to identify potential sites of structural plasticity induced by adaptation. One week of training led to (1) an increment in local gray matter concentration over the hand area of the contralateral primary motor cortex and (2) an increase in fractional anisotropy in an area underneath this region that correlated with the speed of learning. Moreover, the change in gray matter concentration measured immediately after training predicted improvements in the speed of learning during readaptation 1 year later. Our study suggests that motor adaptation induces structural plasticity in primary motor circuits. In addition, it provides the first piece of evidence indicating that early structural changes induced by motor learning may impact on behavior up to 1 year after training. PMID:21849541
Landi, Sofia M; Baguear, Federico; Della-Maggiore, Valeria
Long-term deficits in episodic memory after ischemic stroke: evaluation and prediction of verbal and visual memory performance based on lesion characteristics.
We investigated the relationship between ischemic lesion characteristics (hemispheric side, cortical and subcortical level, volume) and memory performance, 1 year after stroke. Verbal and visual memory of 86 patients with stroke were assessed with Rey Auditory-Verbal Learning Test and the Doors Test, respectively. Lesion characteristics and presence of white matter lesions were assessed on magnetic resonance imaging early after stroke. Multiple regression analyses were used to investigate prediction of verbal and visual memory performance by lesion side (left v right hemisphere), lesion level (cortical v subcortical), and lesion volume. We controlled for the influence of demographic characteristics, language disability, and visuospatial difficulties on memory. The results demonstrated that poor verbal memory (immediate and delayed recall and recognition) could be predicted by lesion characteristics: patients with left hemispheric, subcortical, and large lesions showed poor memory performance. Poor visual recognition memory could not be predicted by lesion characteristics but only by low educational level. Our results suggest that lesion characteristics play an important role in episodic verbal memory poststroke if demographic and clinical characteristics are taken into account. PMID:19251189
Schouten, Eveline A; Schiemanck, Sven K; Brand, Nico; Post, Marcel W M
Short-term retention of a single word relies on retrieval from long-term memory when both rehearsal and refreshing are disrupted.
Many working memory (WM) models propose that the focus of attention (or primary memory) has a capacity limit of one to four items, and therefore, that performance on WM tasks involves retrieving some items from long-term (or secondary) memory (LTM). In the present study, we present evidence suggesting that recall of even one item on a WM task can involve retrieving it from LTM. The WM task required participants to make a deep (living/nonliving) or shallow ("e"/no "e") level-of-processing (LOP) judgment on one word and to recall the word after a 10-s delay on each trial. During the delay, participants either rehearsed the word or performed an easy or a hard math task. When the to-be-remembered item could be rehearsed, recall was fast and accurate. When it was followed by a math task, recall was slower, error-prone, and benefited from a deeper LOP at encoding, especially for the hard math condition. The authors suggest that a covert-retrieval mechanism may have refreshed the item during easy math, and that the hard math condition shows that even a single item cannot be reliably held in WM during a sufficiently distracting task-therefore, recalling the item involved retrieving it from LTM. Additionally, performance on a final free recall (LTM) test was better for items recalled following math than following rehearsal, suggesting that initial recall following math involved elaborative retrieval from LTM, whereas rehearsal did not. The authors suggest that the extent to which performance on WM tasks involves retrieval from LTM depends on the amounts of disruption to both rehearsal and covert-retrieval/refreshing maintenance mechanisms. PMID:24500778
Rose, Nathan S; Buchsbaum, Bradley R; Craik, Fergus I M
Sleep deprivation during a specific 3-hour time window post-training impairs hippocampal synaptic plasticity and memory.
Sleep deprivation disrupts hippocampal function and plasticity. In particular, long-term memory consolidation is impaired by sleep deprivation, suggesting that a specific critical period exists following learning during which sleep is necessary. To elucidate the impact of sleep deprivation on long-term memory consolidation and synaptic plasticity, long-term memory was assessed when mice were sleep deprived following training in the hippocampus-dependent object place recognition task. We found that 3h of sleep deprivation significantly impaired memory when deprivation began 1h after training. In contrast, 3 h of deprivation beginning immediately post-training did not impair spatial memory. Furthermore, a 3-h sleep deprivation beginning 1h after training impaired hippocampal long-term potentiation (LTP), whereas sleep deprivation immediately after training did not affect LTP. Together, our findings define a specific 3-h critical period, extending from 1 to 4h after training, during which sleep deprivation impairs hippocampal function. PMID:24380868
Prince, Toni-Moi; Wimmer, Mathieu; Choi, Jennifer; Havekes, Robbert; Aton, Sara; Abel, Ted
Long term effects of murine postnatal exposure to decabromodiphenyl ether (BDE-209) on learning and memory are dependent upon APOE polymorphism and age
DEFF Research Database (Denmark)
Polybrominated diphenyl ethers (PBDEs) are a group of chemicals widely used as flame retardants; the lower brominated forms (1-5 bromine atoms) are highly neurotoxic and are presently not in commercial use. The highest brominated, the decabromodiphenyl ether (BDE-209) remains in use and its adverse and persistent effects are subject to debate. Of special concern are developmental exposures that can disrupt later-in-life adult health or aging. In this study, we investigated the effects of postnatal exposure to BDE-209 in combination with apolipoprotein E (apoE) genotype, a genetic factor that is associated with varied vulnerability for the development of neurodegenerative diseases. On postnatal day 10, transgenic mice of both sexes carrying apoE2, apoE3 and apoE4 were orally exposed to 0, 10 or 30mg/kg of BDE-209. Spatial reference memory was assessed in a Morris Water Maze (MWM) task at 4 and 12months of age. The levels of the brain-derived neurotrophic factor (BDNF) were determined in hippocampus and frontalcortex of mice at 5months of age. Mice carrying different apoE polymorphisms showed differences in the acquisition and retention of the spatial navigation task both at 4 and 12months of age. Postnatal exposure to BDE-209 induced long term effects in spatial learning, which were dependent upon age, sex and apoE genotype; these effects were more evident in apoE3 mice. BDNF levels were lower in the frontal cortex of apoE4 mice and higher in the hippocampus of exposed mice, independent of the genotype. The results of the present study provide evidence of long-lasting effects in spatial learning and memory after early exposure to BDE-209. Developmental exposure to this neurotoxicant may contribute to cognitive decline and abnormal aging.
Reverte, Ingrid; Klein, Anders Bue
Protein Kinase M Maintains Long-Term Sensitization and Long-Term Facilitation in Aplysia
Digital Repository Infrastructure Vision for European Research (DRIVER)
How the brain maintains long-term memories is one of the major outstanding questions in modern neuroscience. Evidence from mammalian studies indicates that activity of a protein kinase C isoform, PKM?, plays a critical role in the maintenance of long-term memory. But the range of memories whose persistence depends on PKM?, and the mechanisms that underlie PKM?'s effect on long-term memory, remain obscure. Recently, a PKM isoform, known as PKM Apl III, was cloned from the nervous system of ...
Cai, Diancai; Pearce, Kaycey; Chen, Shanping; Glanzman, David L.
Robust Recall and Long-Term Memory T-Cell Responses Induced by Prime-Boost Regimens with Heterologous Live Viral Vectors Expressing Human Immunodeficiency Virus Type 1 Gag and Env Proteins
Digital Repository Infrastructure Vision for European Research (DRIVER)
We investigated long-term memory and recall cellular immune responses to human immunodeficiency virus type 1 (HIV-1) Env and Gag proteins elicited by recombinant vesicular stomatitis viruses (VSVs) expressing Env and Gag. More than 7 months after a single vaccination with VSV-Env, ?6% of CD8+ splenocytes stained with major histocompatibility complex class I tetramers containing the Env p18-I10 immunodominant peptide and showed a memory phenotype (CD44Hi). The level of tetramer-positive cell...
Haglund, Karl; Leiner, Ingrid; Kerksiek, Kristen; Buonocore, Linda; Pamer, Eric; Rose, John K.
The Committee of the Long Term Collections (CLT) asks for your attention for the following message from a young Peruvian scientist, following the earthquake which devastated part of her country a month ago.
Collectes � long terme
Long-term anti-HBs antibody persistence and immune memory in children and adolescents who received routine childhood hepatitis B vaccination.
This paper presents data from two studies that evaluated 5-y and 10-y persistence of antibodies against hepatitis B (HBV) surface antigen (anti-HBs) and immune response to an HBV vaccine challenge in children and adolescents who had received three doses of a HBV vaccine in infancy as part of routine clinical practice [NCT00519649/NCT00984139]. Anti-HBs antibody concentrations ? 10 mIU/ml persisted in 83.3% (95% confidence interval [CI]: 78.5�87.5) and 78.3% (95% CI: 73.1�83.0) of subjects aged 7�8 y and 12�13 y, respectively 5�10 y after infant vaccination. One month postchallenge dose, 98.2% (95% CI: 95.9�99.4) and 93.7% (95% CI: 90.2�96.2) of subjects in the two age groups, respectively had anti-HBs antibody concentrations ? 100 mIU/ml. Overall, 99.6% (95% CI: 98�100) and 97.2% (95% CI: 94.5�98.8) of subjects aged 7�8 y and 12�13 y mounted an anamnestic response to the HBV challenge dose, which was well-tolerated. Healthy children aged 7�8 y and adolescents aged 12�13 y received three doses of a monovalent pediatric HBV vaccine (10 ?g of HBsAg) before 18 mo of age. Serum samples collected before and one month post-HBV vaccine challenge dose were tested for anti-HBs antibody concentrations. Safety assessments were made for the HBV vaccine challenge dose. A three-dose childhood HBV immunization regimen induced persistence of antibodies against HBV infection for 10 y, up to adolescence. This vaccination regimen also conferred long-term immune memory against HBV as evidenced by the strong anamnestic response to the HBV vaccine challenge, despite waning anti-HBs antibody levels. PMID:22508412
Behre, Ulrich; Bleckmann, Gerhard; Crasta, Priya Diana; Leyssen, Maarten; Messier, Marc; Jacquet, Jeanne-Marie; Hardt, Karin
Immunization of mice with the nef gene from Human Immunodeficiency Virus type 1: Study of immunological memory and long-term toxicology
Directory of Open Access Journals (Sweden)
Full Text Available Abstract Background The human immunodeficiency virus type 1 (HIV-1 regulatory protein, Nef, is an attractive vaccine target because it is involved in viral pathogenesis, is expressed early in the viral life cycle and harbors many T and B cell epitopes. Several clinical trials include gene-based vaccines encoding this protein. However, Nef has been shown to transform certain cell types in vitro. Based on these findings we performed a long-term toxicity and immunogenicity study of Nef, encoded either by Modified Vaccinia virus Ankara or by plasmid DNA. BALB/c mice were primed twice with either DNA or MVA encoding Nef and received a homologous or heterologous boost ten months later. In the meantime, the Nef-specific immune responses were monitored and at the time of sacrifice an extensive toxicological evaluation was performed, where presence of tumors and other pathological changes were assessed. Results The toxicological evaluation showed that immunization with MVAnef is safe and does not cause cellular transformation or other toxicity in somatic organs. Both DNAnef and MVAnef immunized animals developed potent Nef-specific cellular responses that declined to undetectable levels over time, and could readily be boosted after almost one year. This is of particular interest since it shows that plasmid DNA vaccine can also be used as a potent late booster of primed immune responses. We observed qualitative differences between the T cell responses induced by the two different vectors: DNA-encoded nef induced long-lasting CD8+ T cell memory responses, whereas MVA-encoded nef induced CD4+ T cell memory responses. In terms of the humoral immune responses, we show that two injections of MVAnef induce significant anti-Nef titers, while repeated injections of DNAnef do not. A single boost with MVAnef could enhance the antibody response following DNAnef prime to the same level as that observed in animals immunized repeatedly with MVAnef. We also demonstrate the possibility to boost HIV-1 Nef-specific immune responses using the MVAnef construct despite the presence of potent anti-vector immunity. Conclusion This study shows that the nef gene vectored by MVA does not induce malignancies or other adverse effects in mice. Further, we show that when the nef gene is delivered by plasmid or by a viral vector, it elicits potent and long-lasting immune responses and that these responses can be directed towards a CD4+ or a CD8+ T cell response depending on the choice of vector.
Engstr�m Gunnel
Influence of Pre-Training Predator Stress on the Expression of c-fos mRNA in the Hippocampus, Amygdala, and Striatum Following Long-Term Spatial Memory Retrieval.
We have studied the influence of pre-training psychological stress on the expression of c-fos mRNA following long-term spatial memory retrieval. Rats were trained to learn the location of a hidden escape platform in the radial-arm water maze, and then their memory for the platform location was assessed 24?h later. Rat brains were extracted 30?min after the 24-h memory test trial for analysis of c-fos mRNA. Four groups were tested: (1) Rats given standard training (Standard); (2) Rats given cat exposure (Predator Stress) 30?min prior to training (Pre-Training Stress); (3) Rats given water exposure only (Water Yoked); and (4) Rats given no water exposure (Home Cage). The Standard trained group exhibited excellent 24?h memory which was accompanied by increased c-fos mRNA in the dorsal hippocampus and basolateral amygdala (BLA). The Water Yoked group exhibited no increase in c-fos mRNA in any brain region. Rats in the Pre-Training Stress group were classified into two subgroups: good and bad memory performers. Neither of the two Pre-Training Stress subgroups exhibited a significant change in c-fos mRNA expression in the dorsal hippocampus or BLA. Instead, stressed rats with good memory exhibited significantly greater c-fos mRNA expression in the dorsolateral striatum (DLS) compared to stressed rats with bad memory. This finding suggests that stressed rats with good memory used their DLS to generate a non-spatial (cue-based) strategy to learn and subsequently retrieve the memory of the platform location. Collectively, these findings provide evidence at a molecular level for the involvement of the hippocampus and BLA in the retrieval of spatial memory and contribute novel observations on the influence of pre-training stress in activating the DLS in response to long-term memory retrieval. PMID:21738501
Vanelzakker, Michael B; Zoladz, Phillip R; Thompson, Vanessa M; Park, Collin R; Halonen, Joshua D; Spencer, Robert L; Diamond, David M
It is the time of the year when our fireman colleagues go around the laboratory for their traditional calendars sale. A part of the money of the sales will be donated in favour of the long-term collections. We hope that you will welcome them warmly.
Comit� des collectes � long terme
PDE4 inhibition enhances hippocampal synaptic plasticity in vivo and rescues MK801-induced impairment of long-term potentiation and object recognition memory in an animal model of psychosis
Digital Repository Infrastructure Vision for European Research (DRIVER)
Inhibition of phosphodiesterase type 4 (PDE4) by rolipram (4-(3-(cyclopentyloxy)-4-methoxyphenyl)-pyrrolidin-2-one) has been the focus of many behavioral and molecular studies in the recent years. Rolipram exhibits memory-enhancing effects in rodents. In vitro studies have shown that long-term potentiation (LTP), which may comprise a cellular substrate for learning, is also enhanced by rolipram. However, effects have not been assessed in vivo. Rolipram has antipsychotic properties. Psychosis ...
Wiescholleck, V.; Manahan-vaughan, D.
High levels of anti-human immunodeficiency virus type 1 (HIV-1) memory cytotoxic T-lymphocyte activity and low viral load are associated with lack of disease in HIV-1-infected long-term nonprogressors.
Digital Repository Infrastructure Vision for European Research (DRIVER)
Lack of disease in long-term nonprogressors with human immunodeficiency virus type 1 (HIV-1) infection was strongly associated with very low copy numbers of HIV-1 DNA and RNA in peripheral blood mononuclear cells and plasma and the presence of high levels of anti-HIV-1 CD8+ memory cytotoxic T lymphocytes specific for Gag, Pol, and Env, compared with levels present in intermediate and advanced progressors. CD8+ memory cytotoxic T lymphocytes may have an important role in controlling HIV-1 repl...
Rinaldo, C.; Huang, X. L.; Fan, Z. F.; Ding, M.; Beltz, L.; Logar, A.; Panicali, D.; Mazzara, G.; Liebmann, J.; Cottrill, M.
Hippocampus-dependent and -independent theta-networks of active maintenance
Digital Repository Infrastructure Vision for European Research (DRIVER)
"Recent studies in humans and animals raise the possibility that actively maintaining a detailed memory of a scene within working memory may require the hippocampus, a brain structure better known for its role in long-term memory. We show that the hippocampus is behaviorally and functionally critical for configural-relational (CR) maintenance by orchestrating the synchrony of occipital and temporal brain regions in the theta-frequency range. Using magnetoencephalography in healthy adults...
Cashdollar, N.; Malecki, U.; Rugg-gunn, F. J.; Duncan, J. S.; Lavie, N.; Duzel, E.
Antidepressant suppression of Non-REM sleep spindles and REM sleep impairs hippocampus-dependent learning while augmenting striatal-dependent learning
Digital Repository Infrastructure Vision for European Research (DRIVER)
Rapid eye movement (REM) sleep enhances hippocampus-dependent associative memory but REM deprivation has little impact on striatal-dependent procedural learning. Antidepressant medications are known to inhibit REM sleep but it is not well understood if antidepressant treatments impact learning and memory. We explored antidepressant REM suppression effects on learning by training animals daily on a spatial task under familiar and novel conditions followed by training on a procedural memory tas...
Watts, Alain; Gritton, Howard J.; Sweigart, Jamie; Poe, Gina R.
Long-Term Memory Deficits are Associated with Elevated Synaptic ERK1/2 Activation and Reversed by mGluR5 Antagonism in an Animal Model of Autism.
A significant proportion of patients with autism exhibit some degree of intellectual disability. The BTBR T(+) Itpr3(tf)/J mouse strain exhibits behaviors that align with the major diagnostic criteria of autism. To further evaluate the BTBR strain's cognitive impairments, we quantified hippocampus-dependent object location memory (OLM) and found that one-third of the BTBR mice exhibited robust memory, whereas the remainder did not. Fluorescence deconvolution tomography was used to test whether synaptic levels of activated extracellular signal-regulated kinase 1/2 (ERK1/2), a protein that contributes importantly to plasticity, correlate with OLM scores in individual mice. In hippocampal field CA1, the BTBRs had fewer post-synaptic densities associated with high levels of phosphorylated (p-) ERK1/2 as compared with C57BL/6 mice. Although counts of p-ERK1/2 immunoreactive synapses did not correlate with OLM performance, the intensity of synaptic p-ERK1/2 immunolabeling was negatively correlated with OLM scores across BTBRs. Metabotropic glutamate receptor (mGluR) 5 signaling activates ERK1/2. Therefore, we tested whether treatment with the mGluR5 antagonist MPEP normalizes synaptic and learning measures in BTBR mice: MPEP facilitated OLM and decreased synaptic p-ERK1/2 immunolabeling intensity without affecting numbers of p-ERK1/2+ synapses. In contrast, semi-chronic ampakine treatment, which facilitates memory in other models of cognitive impairment, had no effect on OLM in BTBRs. These results suggest that intellectual disabilities associated with different neurodevelopmental disorders on the autism spectrum require distinct therapeutic strategies based on underlying synaptic pathology. PMID:24448645
Seese, Ronald R; Maske, Anna R; Lynch, Gary; Gall, Christine M
Dynamical model of long-term synaptic plasticity
Digital Repository Infrastructure Vision for European Research (DRIVER)
Long-term synaptic plasticity leading to enhancement in synaptic efficacy (long-term potentiation, LTP) or decrease in synaptic efficacy (long-term depression, LTD) is widely regarded as underlying learning and memory in nervous systems. LTP and LTD at excitatory neuronal synapses are observed to be induced by precise timing of pre- and postsynaptic events. Modification of synaptic transmission in long-term plasticity is a complex process involving many pathways; for example, it is also known...
Abarbanel, Henry D. I.; Huerta, R.; Rabinovich, M. I.
Long-term functional recovery from age-induced spatial memory impairments by nerve growth factor gene transfer to the rat basal forebrain.
Digital Repository Infrastructure Vision for European Research (DRIVER)
Nerve growth factor (NGF) stimulates functional recovery from cognitive impairments associated with aging, either when administered as a purified protein or by means of gene transfer to the basal forebrain. Because gene transfer procedures need to be tested in long-term experimental paradigms to assess their in vivo efficiency, we have used ex vivo experimental gene therapy to provide local delivery of NGF to the aged rat brain over a period of 2.5 months by transplanting immortalized central...
Marti?nez-serrano, A.; Fischer, W.; So?derstro?m, S.; Ebendal, T.; Bjo?rklund, A.
The coumarin scopoletin potentiates acetylcholine release from synaptosomes, amplifies hippocampal long-term potentiation and ameliorates anticholinergic- and age-impaired memory
Digital Repository Infrastructure Vision for European Research (DRIVER)
In a previous study the simple, naturally derived coumarin scopoletin (SCT) was identified as an inhibitor of acetylcholinesterase (AChE), using a pharmacophore-based virtual screening approach. In this study the potential of SCT as procholinergic and cognition-enhancing therapeutic was investigated in a more detailed way, using different experimental approaches like measuring newly synthesized acetylcholine (ACh) in synaptosomes, long-term potentiation (LTP) experiments in hippocampal slices...
Hornick, A.; Lieb, A.; Vo, N. P.; Rollinger, J. M.; Stuppner, H.; Prast, H.
Cytoplasmic to nuclear localization of fatty-acid binding protein correlates with specific forms of long-term memory in Drosophila
Digital Repository Infrastructure Vision for European Research (DRIVER)
We recently reported evidence implicating fatty-acid binding protein (Fabp) in the control of sleep and memory formation. We used Drosophila melanogaster to examine the relationship between sleep and memory through transgenic overexpression of mouse brain-Fabp, Fabp7, or the Drosophila Fabp homolog, (dFabp). The key findings are that 1) a genetically induced increase in daytime consolidated sleep (naps) correlates with an increase in cognitive performance, and 2) a late �window� of memory...
Gerstner, Jason R.; Vanderheyden, William M.; Shaw, Paul J.; Landry, Charles F.; Yin, Jerry Cp
Slave to the Rhythm: Experimental Tests of a Model for Verbal Short-Term Memory and Long-Term Sequence Learning
Three experiments tested predictions of a neural network model of phonological short-term memory that assumes separate representations for order and item information, order being coded via a context-timing signal [Burgess, N., & Hitch, G. J. (1999). Memory for serial order: A network model of the phonological loop and its timing. "Psychological�
Hitch, Graham J.; Flude, Brenda; Burgess, Neil
Mice Overexpressing Type 1 Adenylyl Cyclase Show Enhanced Spatial Memory Flexibility in the Absence of Intact Synaptic Long-Term Depression
There is significant interest in understanding the contribution of intracellular signaling and synaptic substrates to memory flexibility, which involves new learning and suppression of obsolete memory. Here, we report that enhancement of Ca[superscript 2+]-stimulated cAMP signaling by overexpressing type 1 adenylyl cyclase (AC1) facilitated�
Zhang, Ming; Wang, Hongbing
Transcranial focal electrical stimulation via tripolar concentric ring electrodes does not modify the short- and long-term memory formation in rats evaluated in the novel object recognition test.
Noninvasive transcranial focal electrical stimulation (TFS) via tripolar concentric ring electrodes (TCREs) has been under development as an alternative/complementary therapy for seizure control. Transcranial focal electrical stimulation has shown efficacy in attenuating penicillin-, pilocarpine-, and pentylenetetrazole-induced acute seizures in rat models. This study evaluated the effects of TFS via TCREs on the memory formation of healthy rats as a safety test of TFS. Short- and long-term memory formation was tested after the application of TFS using the novel object recognition (NOR) test. The following independent groups were used: na�ve, control (without TFS), and TFS (treated). The na�ve, control, and stimulated groups spent more time investigating the new object than the familiar one during the test phase. Transcranial focal electrical stimulation via TCREs given once does not modify the short- and long-term memory formation in rats in the NOR test. Results provide an important step towards a better understanding for the safe usage of TFS via TCREs. PMID:23419871
Rogel-Salazar, G; Luna-Mungu�a, H; Stevens, K E; Besio, W G
Introduction: Long term prediction
Energy Technology Data Exchange (ETDEWEB)
Making a decision upon the right choice of a material appropriate to a given application should be based on taking into account several parameters as follows: cost, standards, regulations, safety, recycling, chemical properties, supplying, transformation, forming, assembly, mechanical and physical properties as well as the behaviour in practical conditions. Data taken from a private communication (J.H.Davidson) are reproduced presenting the life time range of materials from a couple of minutes to half a million hours corresponding to applications from missile technology up to high-temperature nuclear reactors or steam turbines. In the case of deep storage of nuclear waste the time required is completely different from these values since we have to ensure the integrity of the storage system for several thousand years. The vitrified nuclear wastes should be stored in metallic canisters made of iron and carbon steels, stainless steels, copper and copper alloys, nickel alloys or titanium alloys. Some of these materials are passivating metals, i.e. they develop a thin protective film, 2 or 3 nm thick - the so-called passive films. These films prevent general corrosion of the metal in a large range of chemical condition of the environment. In some specific condition, localized corrosion such as the phenomenon of pitting, occurs. Consequently, it is absolutely necessary to determine these chemical condition and their stability in time to understand the behavior of a given material. In other words the corrosion system is constituted by the complex material/surface/medium. For high level nuclear wastes the main features for resolving problem are concerned with: geological disposal; deep storage in clay; waste metallic canister; backfill mixture (clay-gypsum) or concrete; long term behavior; data needed for modelling and for predicting; choice of appropriate solution among several metallic candidates. The analysis of the complex material/surface/medium is of great importance not only in the case of the topics of this workshop but also in other cases because the corrosion resistance of a given material is not an intrinsic property. In case of long term disposal it is essential to have very accurate data for modelling and predicting the behavior of materials engaged for the deep storage of high level nuclear wastes. It is the purpose of this workshop to bring together articles which have a significant contribution to make, and which take into account all the parameters of importance so that appropriate decision can be taken.
Beranger, G. [Universite de Technologie de Compiegne, ROBERVAL Laboratory, CNRS 6066, 60205 Compiegne Cedex (France)
ACKNOWLEDGMENTS The Long-Term Collections (CLT) committee would like to warmly thank its faithful donors who, year after year, support our actions all over the world. Without you, all this would not be possible. We would like to thank, in particular, the CERN Firemen�s Association who donated 5000 CHF in the spring thanks to the sale of their traditional calendar, and the generosity of the CERN community. A huge thank you to the firemen for their devotion to our cause. And thank you to all those who have opened their door, their heart, and their purses! Similarly, we warmly thank the CERN Yoga Club once again for its wonderful donation of 2000 CHF we recently received. We would also like to tell you that all our projects are running well. Just to remind you, we are currently supporting the activities of the �R�flexe-Partage� Association in Mali; the training centre of �Education et D�veloppement� in Abomey, Benin; and the orphanage and ...
Rapid and Reversible Impairments of Short- and Long-Term Social Recognition Memory Are Caused by Acute Isolation of Adult Rats via Distinct Mechanisms
Digital Repository Infrastructure Vision for European Research (DRIVER)
Mammalian social organizations require the ability to recognize and remember individual conspecifics. This social recognition memory (SRM) can be examined in rodents using their innate tendency to investigate novel conspecifics more persistently than familiar ones. Here we used the SRM paradigm to examine the influence of housing conditions on the social memory of adult rats. We found that acute social isolation caused within few days a significant impairment in acquisition of short-term SRM ...
Circadian modulation of long-term sensitization in Aplysia
Digital Repository Infrastructure Vision for European Research (DRIVER)
As the mechanisms for learning and memory are elucidated, modulation of learning and memory becomes a central issue. We studied the modulation of learning and memory by investigating the circadian regulation of short- and long-term sensitization of the siphon withdrawal reflex in Aplysia. We found that Aplysia exhibited diurnal and circadian rhythms of long-term sensitization (LTS) with significantly greater LTS occurring when animals were trained and tested during the day relative to those t...
Fernandez, Raymond I.; Lyons, Lisa C.; Levenson, Jonathan; Khabour, Omar; Eskin, Arnold
Evaluating long term forecasts
International Nuclear Information System (INIS)
The U.S. Department of Energy's Energy Information Administration (EIA), and its predecessor organizations, has published projections of U.S. energy production, consumption, distribution and prices annually for over 30 years. A natural issue to raise in evaluating the projections is an assessment of their accuracy compared to eventual outcomes. A related issue is the determination of the sources of 'error' in the projections that are due to differences between the actual versus realized values of the associated assumptions. One way to do this would be to run the computer-based model from which the projections are derived at the time the projected values are realized, using actual rather than assumed values for model assumptions; and, compare these results to the original projections. For long term forecasts, this approach would require that the model's software and hardware configuration be archived and available for many years, possibly decades, into the future. Such archival creates many practical problems; and, in general, it is not being done. This paper reports on an alternative approach for evaluating the projections. In the alternative approach, the model is run many times for cases in which important assumptions are changed individually and in combinations. A database is assembled from the solutions and a regression analysis is conducted for each important projected variable with the associated assumptions chosen as exogenous variables. When actual data are eventually available, the regression results are then used to estimate the sources of the differences in the projections of the endogenous variables compared to their eventual outcomes. The results presented here are for residential and commercial sector natural gas and electricity consumption. (author)
The Committee would like to thank all those, from near and far, who kindly gave donations to the collection organized at the time of the sudden death of our friend and colleague Stephen O'NEALE The sum of 3,615 francs will be sent to the INEPE Association for the education of children in Quito, Ecuador. We are deeply grateful for this gesture from Steve's family and hope that they find comfort in knowing that Steve's memory will live on through the children whose daily lives will be improved by this gift.
Major impairments of glutamatergic transmission and long-term synaptic plasticity in the hippocampus of mice lacking the melanin-concentrating hormone receptor-1.
The hypothalamic neuropeptide melanin-concentrating hormone (MCH) plays important roles in energy homeostasis, anxiety, and sleep regulation. Since the MCH receptor-1 (MCH-R1), the only functional receptor that mediates MCH functions in rodents, facilitates behavioral performance in hippocampus-dependent learning tasks, we investigated whether glutamatergic transmission in CA1 pyramidal cells could be modulated in mice lacking the MCH-R1 gene (MCH-R1(-/-)). We found that both ?-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) and N-methyl-d-aspartate (NMDA) receptor-mediated transmissions were diminished in the mutant mice compared with their controls. This deficit was explained, at least in part, by a postsynaptic down-regulation of these receptors since the amplitude of miniature excitatory postsynaptic currents and the NMDA/AMPA ratio were decreased. Long-term synaptic potentiation (LTP) was also impaired in MCH-R1(-/-) mice. This was due to an altered induction, rather than an impaired, expression because repeating the induction stimulus restored LTP to a normal magnitude. In addition, long-term synaptic depression was strongly diminished in MCH-R1(-/-) mice. These results suggest that MCH exerts a facilitatory effect on CA1 glutamatergic synaptic transmission and long-term synaptic plasticity. Recently, it has been shown that MCH neurons fire exclusively during sleep and mainly during rapid eye movement sleep. Thus these findings provide a mechanism by which sleep might facilitate memory consolidation. PMID:20592115
Pachoud, Bastien; Adamantidis, Antoine; Ravassard, Pascal; Luppi, Pierre-Herv�; Grisar, Thierry; Lakaye, Bernard; Salin, Paul-Antoine
The group I metabotropic glutamate receptor mGluR5 is required for fear memory formation and long-term potentiation in the lateral amygdala.
The group I metabotropic glutamate receptor subtype mGluR5 has been shown to play a key role in the modulation of synaptic plasticity. The present experiments examined the function of mGluR5 in the circuitry underlying Pavlovian fear conditioning using neuroanatomical, electrophysiological, and behavioral techniques. First, we show using immunocytochemical and tract-tracing methods that mGluR5 is localized to dendritic shafts and spines in the lateral nucleus of the amygdala (LA) and is postsynaptic to auditory thalamic inputs. In electrophysiological experiments, we show that long-term potentiation at thalamic input synapses to the LA is impaired by bath application of a specific mGluR5 antagonist, 2-methyl-6-(phenyle-thynyl)-pyridine (MPEP), in vitro. Finally, we show that intra-amygdala administration of MPEP dose-dependently impairs the acquisition, but not expression or consolidation, of auditory and contextual fear conditioning. Collectively, the results of this study indicate that mGluR5 in the LA plays a crucial role in fear conditioning and in plasticity at synapses involved in fear conditioning. PMID:12077217
Rodrigues, Sarina M; Bauer, Elizabeth P; Farb, Claudia R; Schafe, Glenn E; LeDoux, Joseph E
Analysis of differential gene expression supports a role for amyloid precursor protein and a protein kinase C substrate (MARCKS) in long-term memory.
Previous work has identified the intermediate and medial part of the hyperstriatum ventrale (IMHV) as a region of the chick brain storing information acquired through the learning process of imprinting. We have examined in this brain region changes in expression of candidate genes involved in memory. Chicks were exposed to a rotating red box and the strength of their preference for it, a measure of learning, determined. Brain samples were removed approximately 24 h after training. Candidate genes whose expressions were different in IMHV samples derived from strongly imprinted chicks relative to those from chicks showing little or no learning were identified using subtractive hybridization. The translation products of two candidate genes were investigated further in samples from the left and right IMHV and from two other brain regions not previously implicated in imprinting, the left and right posterior neostriatum. One of the proteins was the amyloid precursor protein (APP), the other was myristoylated alanine rich C kinase substrate (MARCKS). In the left IMHV the levels of the two proteins increased with the strength of learning. The effects in the right IMHV were not significantly different from those in the left. There were no effects of learning in the posterior neostriatum. This is the first study to relate changes in the amounts of MARCKS and APP proteins to the strength of learning in a brain region known to be a memory store and demonstrates that the systematic identification of protein molecules involved in memory formation is possible. PMID:12653983
Solomonia, R O; Morgan, K; Kotorashvili, A; McCabe, B J; Jackson, A P; Horn, G
Preservation of long-term memory and synaptic plasticity despite short-term impairments in the Tc1 mouse model of Down syndrome
Digital Repository Infrastructure Vision for European Research (DRIVER)
Down syndrome (DS) is a genetic disorder arising from the presence of a third copy of the human chromosome 21 (Hsa21). Recently, O�Doherty and colleagues in an earlier study generated a new genetic mouse model of DS (Tc1) that carries an almost complete Hsa21. Since DS is the most common genetic cause of mental retardation, we have undertaken a detailed analysis of cognitive function and synaptic plasticity in Tc1 mice. Here we show that Tc1 mice have impaired spatial working memory (WM) bu...
Long-Term Effects of Physical Exercise on Verbal Learning and Memory in Middle-Aged Adults: Results of a One-Year Follow-Up Study
Directory of Open Access Journals (Sweden)
Full Text Available A few months of physical exercise have been shown to increase cognition and to modulate brain functions in previously sedentary, mainly older adults. However, whether the preservation of newly gained cognitive capacities requires an active maintenance of the achieved fitness level during the intervention is not yet known. The aim of the present study was to test whether cardiovascular fitness one year after an exercise intervention was linked to cognitive variables. Twenty-five healthy participants (42�57 years of age took part in a follow-up assessment one year after the end of a supervised exercise intervention. Measurements included a cardiovascular fitness test, psychometric tests of verbal learning and memory and selective attention as well as questionnaires assessing physical activity and self-efficacy beliefs. Recognition scores of participants with higher cardiovascular fitness at follow-up did not change significantly during the follow-up period; however, the scores of participants with lower cardiovascular fitness decreased. One year after the end of the physical training intervention, previously sedentary participants spent more hours exercising than prior to the intervention. The time participants spent exercising correlated with their self-efficacy beliefs. These results demonstrate a direct link between verbal learning and cardiovascular fitness and show that positive effects of physical interventions on learning and memory do need an active maintenance of cardiovascular fitness.
Brigitte R�der
Influence of a combination of two tetrachlorobiphenyl congeners (PCB 47; PCB 77) on thyroid status, choline acetyltransferase (ChAT) activity, and short- and long-term memory in 30-day-old Sprague-Dawley rats
International Nuclear Information System (INIS)
The important role of thyroid hormones in growth and development, maintenance of body temperature, digestion, cardiac function, and normal brain development can be disrupted by environmental contaminants like polychlorinated biphenyls (PCB). Polychlorinated biphenyls are environmental contaminants that are widespread, persistent, lipophilic, and bioaccumulate through food webs, concentrating in adipose tissue. Placental and lactational PCB exposure of offspring causes metabolic and endocrine disruptions including hypothyroxinemia, spatial learning and memory deficits, neurochemical and neurobehavioral alterations, and reproductive problems. Previous studies in our lab using the individual congeners PCB 47 (2,2',4,4'-tetrachlorobiphenyl, ortho-substituted) and PCB 77 (3,3',4,4'-tetrachlorobiphenyl, non-ortho-substituted) have demonstrated alterations in thyroid hormone levels, alterations in brain choline acetyltransferase (ChAT) activity, and spatial learning deficits. In the present study, pregnant Sprague-Dawley rats were fed a diet with or without a mixture of PCB 47/77 at 1.25 ppm, 12.5 ppm or 25.0 ppm (w/w). Rat pups were swum in the Morris water maze four times a day on days 21-29 in order for the animals to learn the position of a submerged fixed platform. A probe test was run on day 24 (30 min after last swim) for short-term memory, and on day 29 (24 h after the last swim) for long-term memory after removal of the platform. Time spent in the quadrant previously containing the platform was recorded. Rats were decapitated on day 30, serum collected and frozen at -20 deg. ChAT activity was measured radiometrically in basal forebrain and hippocampus. All PCB-treated animals experienced a depression in both triiodothyronine (T3) and thyroxine (T4). The present study found that all doses of PCB depressed ChAT activity in hippocampus with no significant alteration in the basal forebrain. In PCB-treated animals, short-term memory showed a trend toward improvement and long-term memory toward depression, but these trends were not significant. The consequences likely stem from endocrine disruption, especially with regard to the thyroid
Spatial Distribution of Potentiated Synapses in Hippocampus: Dependence on Cellular Mechanisms and Network Properties
Digital Repository Infrastructure Vision for European Research (DRIVER)
Long-term potentiation (LTP) of synaptic transmission, studied intensively in reduced brain preparations such as hippocampal brain slices, is the leading candidate for the cellular/molecular basis of learning and memory. Serious consideration of LTP as underlying information storage in the intact brain, however, requires understanding how LTP can be induced selectively at specific synaptic sites in a neural system when the mechanisms underlying LTP are regulated by other structural and functi...
Yeckel, M. F.; Berger, T. W.
Altered emotionality, hippocampus-dependent performance and expression of NMDA receptor subunit mRNAs in chronically stressed mice.
N-Methyl-D-aspartate receptor (NMDAR)-mediated neurotransmission in the hippocampus is implicated in cognitive and emotional disturbances during stress-related disorders. Here, using quantitative RT-PCR, we investigated the hippocampal expression of NR2A, NR2B and NR1 subunit mRNAs in a mouse stress paradigm that mimics clinically relevant conditions of simultaneously affected emotionality and hippocampus-dependent functions. A 2-week stress procedure, which comprised ethologically valid stressors, exposure to a rat and social defeat, was applied to male C57BL/6J mice. For predation stress, mice were introduced into transparent containers that were placed in a rat home cage during the night; social defeat was applied during the daytime using aggressive CD1 mice. This treatment impaired hippocampus-dependent performance during contextual fear conditioning. A correlation between this behavior and food displacement performance was demonstrated, suggesting that burrowing behavior is affected by the stress procedure and is hippocampus-dependent. Stressed mice (n?=?22) showed behavioral invigoration and anomalous anxiolytic-like profiles in the O-maze and brightly illuminated open field, unaltered short-term memory in the step-down avoidance task and enhanced aggressive traits, as compared to non-stressed mice (n?=?10). Stressed mice showed increased basal serum corticosterone concentrations, hippocampal mRNA expression for the NR2A subunit of the NMDAR and in the NR2A/NR2B ratio; mRNA expression of NR2B and NR1 was unchanged. Thus, stress-induced aberrations in both hippocampal-dependent performance and emotional abnormalities are associated with alterations in hippocampal mRNA NR2A levels and the NR2A/NR2B ratio and not with mRNA expression of NR2B or NR1. PMID:24308441
Costa-Nunes, Jo�o; Zubareva, Olga; Ara�jo-Correia, Margarida; Valen�a, Andreia; Schroeter, Careen A; Pawluski, Jodi L; Vignisse, Julie; Steinbusch, Hellen; Hermes, Denise; Phillipines, Marjan; Steinbusch, Harry M W; Strekalova, Tatyana
Persistence of immunologic memory in long-term hemodialysis patients and healthcare workers given hepatitis B vaccine: role of a booster dose on antibody response.
Hepatitis B (HB) vaccine is effective in producing protection against HB virus infection, but the persistence of immunity remains largely unknown. Seventy-six hemodialysis (HD) patients (60 after primary HB vaccination and 16 with natural immunity) and 46 healthcare workers (32 after primary HB vaccination and 14 with natural immunity) were followed up for 10 years to evaluate the persistence of immunity. Ten years after vaccination, the analysis showed a lower seroconversion rate (38 vs. 75%, p < 0.001) in HD patients as compared with healthcare workers. In the follow-up period, the protective immunity developed through HB virus infection also showed a lower seroconversion rate (44 vs. 86%, p < 0.025) in HD patients as compared with healthcare workers. To assess the status of immunologic memory, we administered a booster dose of HB vaccine 3-12 years (mean 6.7 +/- 0.6 years) after primary vaccination in a selected group of 37 HD patients who presented a decline of their antibodies or were nonresponders. In another group of 12 healthcare workers who had a decline of their antibodies, we also administered a booster dose of HB vaccine 5-8 years (mean 5.8 +/- 0.3 years) after primary vaccination. Nineteen of the 37 HD patients (51%) presented an anamnestic response to the booster dose, and 15 of these (40%) were high responders. All of the healthcare workers responded to the booster dose with a high antibody response. We conclude that patients undergoing HD not only have lower rates of immunization to HB than healthy adults, but also that these are frequently transient. Booster doses after a primary course of vaccine are effective in about the half of HD patients who presented a decline of their antibodies or were nonresponders but whether they are necessary is unclear. The majority of healthcare workers continue to have high levels of protective HBs antibody for at least 10 years and routine boosters are not required. PMID:11549899
Peces, R; Laur�s, A S
The role of long-term oxygen therapy in the management of patients with hypoxemia is discussed. A brief history of the use of long-term oxygen therapy and its benefits is provided. The actual prescription of long-term oxygen therapy and reimbursement issues are reviewed. The use of long-term oxygen therapy, particularly in the home and for travel is addressed. In recent times, the focus of oxygen therapy delivery has shifted to allow patients receiving repeated oxygen therapy to have increased mobility. Lighter and more portable equipment is now used, and oxygen-conserving devices have been developed that allow the patient's oxygen supply to last longer. An update on this equipment and these devices is provided. PMID:11172580
DesRosiers, A; Russo, R
Long Term Survivors of Glioblastoma
Directory of Open Access Journals (Sweden)
Full Text Available There is no generally accepted definition of long-term GBM survivors (LTGBMS. Usually most authors define long-term GBM survivor as a patient who survives at least 3 years after the histological diagnosis of glioblastoma. LTGBMS are uncommon and are reported to occur in 0.5%-16% of cases. In our ENOK (Ege Neuro-Oncology Council cases we have 12 out of 372 GBM patients who survived more than 3 years (3.2%. The clinical and molecular factors that contribute to long-term survival are still unknown. Authors underline the association of glioblastoma long-term survival with prognostically favorable clinical factors, in particular young age and good initial performance score (KPS as well as MGMT promotor hypermethylation.
Nezih OKTAR
Multiple components of eIF4F are required for protein synthesis-dependent hippocampal long-term potentiation.
Persistent forms of synaptic plasticity are widely thought to require the synthesis of new proteins. This feature of long-lasting forms of plasticity largely has been demonstrated using inhibitors of general protein synthesis, such as either anisomycin or emetine. However, these drugs, which inhibit elongation, cannot address detailed questions about the regulation of translation initiation, where the majority of translational control occurs. Moreover, general protein synthesis inhibitors cannot distinguish between cap-dependent and cap-independent modes of translation initiation. In the present study, we took advantage of two novel compounds, 4EGI-1 and hippuristanol, each of which targets a different component of the eukaryotic initiation factor (eIF)4F initiation complex, and investigated their effects on long-term potentiation (LTP) at CA3-CA1 synapses in the hippocampus. We found that 4EGI-1 and hippuristanol both attenuated long-lasting late-phase LTP induced by two different stimulation paradigms. We also found that 4EGI-1 and hippuristanol each were capable of blocking the expression of newly synthesized proteins immediately after the induction of late-phase LTP. These new pharmacological tools allow for a more precise dissection of the role played by translational control pathways in synaptic plasticity and demonstrate the importance of multiple aspects of eIF4F in processes underlying hippocampal LTP, laying the foundation for future studies investigating the role of eIF4F in hippocampus-dependent memory processes. PMID:23054596
Hoeffer, Charles A; Santini, Emanuela; Ma, Tao; Arnold, Elizabeth C; Whelan, Ashley M; Wong, Helen; Pierre, Philippe; Pelletier, Jerry; Klann, Eric
... making your decisions known. Costs & How to Pay Long-term care is expensive, but there are several ways to pay for the care you may need. Share page: Medicare Medicare only covers medically necessary care and focuses on medical acute care , such as doctor visits, drugs, and hospital ...
Spine Expansion and Stabilization Associated with Long-term Potentiation
Digital Repository Infrastructure Vision for European Research (DRIVER)
Stable expression of long-term synaptic plasticity is critical for the developmental refinement of neural circuits and for some forms of learning and memory. Although structural remodeling of dendritic spines is associated with the stable expression of long term potentiation (LTP), the relationship between structural and physiological plasticity remains unclear. To define whether these two processes are related or distinct, we simultaneously monitored EPSPs and dendritic spines, using combine...
Yang, Yunlei; Wang, Xiao-bin; Frerking, Matthew; Zhou, Qiang
Long-term potentiation and the ageing brain.
Digital Repository Infrastructure Vision for European Research (DRIVER)
Ageing is associated with learning and memory impairments. Data are reviewed that suggest that age-related impairments of hippocampal-dependent forms of memory, may be caused, in part, by altered synaptic plasticity mechanisms in the hippocampus, including long-term potentiation (LTP). To the extent that the mechanisms responsible for LTP can be understood, it may be possible to develop therapeutic approaches to alleviate memory decline in normal ageing.
Barnes, C. A.
Nuclear Energy, Long Term Requirements
International Nuclear Information System (INIS)
There are serious warnings about depletion of oil and gas and even more serious warnings about dangers of climate change caused by emission of carbon dioxide. Should developed countries be called to replace CO2 emitting energy sources as soon as possible, and the time available may not be longer then few decades, can nuclear energy answer the call and what are the requirements? Assuming optimistic contribution of renewable energy sources, can nuclear energy expand to several times present level in order to replace large part of fossil fuels use? Paper considers intermediate and long-term requirements. Future of nuclear power depends on satisfactory answers on several questions. First group of questions are those important for near and intermediate future. They deal with economics and safety of nuclear power stations in the first place. On the same time scale a generally accepted concept for radioactive waste disposal is also required. All these issues are in the focus of present research and development. Safer and more economical reactors are targets of international efforts in Generation IV and INPRO projects, but aiming further ahead these innovative projects are also addressing issues such as waste reduction and proliferation resistance. However, even assuming successful technical development of these projects, and there is no reason to doubt it, long term and large-scale nuclear power use is thereby not yet secured. If nuclear power is to play an essential role in the long-term future energy production and in reduction of CO2 emission, than several additional questions must be replied. These questions will deal with long-term nuclear fuel sufficiency, with necessary contribution of nuclear power in sectors of transport and industrial processes and with nuclear proliferation safety. This last issue is more political then technical, thus sometimes neglected by nuclear engineers, yet it will have essential role for the long-term prospects of nuclear power. The status of the intermediate and long-term issues will be discussed, with special attention to the nuclear proliferation issue in view of unfavourable recent development, such as failure of 2005 NPT renewal conference and the Iran and North Korea cases. It will be argued that nuclear proliferation threat is the only really serious obstacle to the large-scale use of nuclear energy. In positive political environment solution of this problem could be possible on the lines of the very early US proposal (so called Baruch plan, UN 1946). Present political developments appear to demand renewed attempt to internationalize proliferation sensitive fuel cycle installations. Reasons will be discussed for a conviction that prospects for this may be better than in 1946. (author)
Energy Technology Data Exchange (ETDEWEB)
Long term data archiving has much value for chemists, not only to retain access to research and product development records, but also to enable new developments and new discoveries. There are some recent regulatory requirements (e.g., FDA 21 CFR Part 11), but good science and good business both benefit regardless. A particular example of the benefits of and need for long term data archiving is the management of data from spectroscopic laboratory instruments. The sheer amount of spectroscopic data is increasing at a scary rate, and the pressures to archive come from the expense to create the data (or recreate it if it is lost) as well as its high information content. The goal of long-term data archiving is to save and organize instrument data files as well as any needed meta data (such as sample ID, LIMS information, operator, date, time, instrument conditions, sample type, excitation details, environmental parameters, etc.). This editorial explores the issues involved in long-term data archiving using the example of Raman spectral databases. There are at present several such databases, including common data format libraries and proprietary libraries. However, such databases and libraries should ultimately satisfy stringent criteria for long term data archiving, including readability for long times into the future, robustness to changes in computer hardware and operating systems, and use of public domain data formats. The latter criterion implies the data format should be platform independent and the tools to create the data format should be easily and publicly obtainable or developable. Several examples of attempts at spectral libraries exist, such as the ASTM ANDI format, and the JCAMP-DX format. On the other hand, proprietary library spectra can be exchanged and manipulated using proprietary tools. As the above examples have deficiencies according to the three long term data archiving criteria, Extensible Markup Language (XML; a product of the World Wide Web Consortium, an independent standards body) as a new data interchange tool is being investigated and implemented. In order to facilitate data archiving, Raman data needs calibration as well as some other kinds of data treatment. Figure 1 illustrates schematically the present situation for Raman data calibration in the world-wide Raman spectroscopy community, and presents some of the terminology used.
Moore, David Steven [Los Alamos National Laboratory
Antenatal maternal long-term hypoxia (LTH) can alter serotonin (5-HT) and calcium (Ca2+) signaling in fetal pulmonary arteries (PAs) and is associated with persistent pulmonary hypertension of the newborn (PPHN). In humans, the antenatal maternal hypoxia can be secondary to smoking, anemia, and chronic obstructive pulmonary disorders. However, the mechanisms of antenatal maternal hypoxia-related PPHN are unresolved. Because both LTH and 5-HT are associated with PPHN, we tested the hypothesis that antenatal maternal LTH can increase 5-HT-mediated PA contraction and associated extracellular Ca2+ influx through L-type Ca2+ channels (CaL), nonselective cation channels (NSCCs), and reverse-mode sodium�calcium exchanger (NCX) in the near-term fetus. We performed wire myography and confocal-Ca2+ imaging approaches on fetal lamb PA (?140 days of gestation) from normoxic ewes or those acclimatized to high-altitude LTH (3801 m) for ?110 days. Long-term hypoxia reduced the potency but not the efficacy of 5-HT-induced PA contraction. Ketanserin (100 nmol/L), a 5-HT2A antagonist, shifted 5-HT potency irrespective of LTH, while GR-55562 (1 �mol/L), a 5-HT1B/D inhibitor, antagonized 5-HT-induced contraction in normoxic fetuses only. Various inhibitors for CaL, NSCC, and reverse-mode NCX were used in contraction studies. Contraction was reliant on extracellular Ca2+ regardless of maternal hypoxia, NSCC was more important to contraction than CaL, and reverse-mode NCX had little or no role in contraction. Long-term hypoxia also attenuated the effects of 2-APB and flufenamic acid and reduced Ca2+ responses observed by imaging studies. Overall, LTH reduced 5HT1B/D function and increased NSCC-related Ca2+-dependent contraction in ovine fetuses, which may compromise pulmonary vascular function in the newborn.
Goyal, Ravi; Papamatheakis, Demosthenes G.; Loftin, Matthew; Vrancken, Kurt; Dawson, Antoinette S.; Osman, Noah J.; Blood, Arlin B.; Pearce, William J.; Longo, Lawrence D.; Wilson, Sean M.
Energy Technology Data Exchange (ETDEWEB)
This update on the long-term economic outlook from the perspective of Ontario Hydro replaces a similar review issued in May 1989, with the main difference from the previous review being an increase in the inflation rate due to the introduction of the federal Goods and Services Tax, scheduled to be introduced on January 1, 1991. The document details changes since the May 1989 review in Ontario economic growth, sectoral distribution of output, inflation and the consumer price index, interest rates, the Canadian dollar exchange rate, and energy prices. Forecast tables are given for energy consumption in Ontario, Canada, the United States, and the Ontario industrial structure. 12 tabs
Long term strategy emphasizes plutonium
International Nuclear Information System (INIS)
The aims of a long term programme for the development of nuclear energy, published by te Atomic Energy Commission in June 1982, are discussed. These include: the use of plutonium in thermal reactors; construction of a 600 MWe demonstration ATR; demonstration of plutonium recycle in LWRs; construction of the 285 MWe prototype fast reactor, Monju; construction of a 1200 t/y reprocessing plant; design of a demonstration centrifuge enrichment plant; and operation of a pilot plant for testing solidification and storage techniques for high level waste. (U.K.)
Selective inhibition of phosphodiesterase 5 enhances glutamatergic synaptic plasticity and memory in mice.
Phosphodiesterases (PDEs) belong to a family of proteins that control metabolism of cyclic nucleotides. Targeting PDE5, for enhancing cellular function, is one of the therapeutic strategies for male erectile dysfunction. We have investigated whether in vivo inhibition of PDE5, which is expressed in several brain regions, will enhance memory and synaptic transmission in the hippocampus of healthy mice. We have found that acute administration of sildenafil, a specific PDE5 inhibitor, enhanced hippocampus-dependent memory tasks. To elucidate the underlying mechanism in the memory enhancement, effects of sildenafil on long-term potentiation (LTP) were measured. The level of LTP was significantly elevated, with concomitant increases in basal synaptic transmission, in mice treated with sildenafil (1 mg/kg/day) for 15 days compared to control mice. These results suggest that moderate PDE5 inhibition enhances memory by increasing synaptic plasticity and transmission in the hippocampus. PMID:23620198
Uthayathas, Subramaniam; Parameshwaran, Kodeeswaran; Karuppagounder, Senthilkumar S; Ahuja, Manuj; Dhanasekaran, Muralikrishnan; Suppiramaniam, Vishnu
Digital Repository Infrastructure Vision for European Research (DRIVER)
Beta-adrenergic receptors (?-ARs) critically modulate long-lasting synaptic plasticity and long-term memory storage in the mammalian brain. Synaptic plasticity is widely believed to mediate memory storage at the cellular level. Long-term potentiation (LTP) is one type of synaptic plasticity that has been linked to memory storage. Activation of ?-ARs can enhance LTP and facilitate long-term memory storage. Interestingly, many of the molecular signaling pathways that are critical for ?-adren...
Three-year-olds�?? memory for a person met only once at the age of 12 months: Very long-term memory revealed by a late-manifesting novelty preference.
DEFF Research Database (Denmark)
This study examined three-year-olds�?? verbal and non-verbal memory for a person met only once after a 28 month interval. Children in the Test group (N=50) had participated in an earlier experiment at our lab at the age of 12 months where they met one of two possible experimenters. At this past event half of the children were tested by one, the other half by the other experimenter. At the follow-up, run by a naïve experimenter, the children were shown two videos from the original experiment in a visual paired comparison task: One with the specific experimenter testing them at the original visit (the Target) and one of the other experimenter (the Foil), with whom they had no experience. When explicitly asked, the children�??s responses did not differ from chance. However, eye-tracking data revealed a late-manifesting novelty preference for the �??Foil�?� person indicating memory for the �??Target�?� person met once before.
Kingo, Osman Skjold; Staugaard, Søren Risløv
NMDA Receptor-Dependent LTD Is Required for Consolidation But Not Acquisition of Fear Memory.
NMDA receptor-dependent long-term depression (NMDAR-LTD) is a form of synaptic plasticity leading to long-lasting decreases in synaptic strength. NMDAR-LTD is essential for spatial and working memory, but its role in hippocampus-dependent fear memory has yet to be determined. Induction of NMDAR-LTD requires the activation of caspase-3 by cytochrome c. Cytochrome c normally resides in mitochondria and during NMDAR-LTD is released from mitochondria, a process promoted by Bax (Bcl-2-associated X protein). Bax induces cell death in apoptosis, but it plays a nonapoptotic role in NMDAR-LTD. Here, we investigated the role of NMDAR-LTD in fear memory in CA1-specific Bax knock-out mice. In hippocampal slices from these knock-out mice, while long-term potentiation of synaptic transmission, basal synaptic transmission, and paired-pulse ratio are intact, LTD in both young and fear-conditioned adult mice is obliterated. Interestingly, in CA1-specific Bax knock-out mice, long-term contextual fear memory is impaired, but the acquisition of fear memory and innate fear are normal. Moreover, these conditional Bax knock-out mice exhibit less behavioral despair. These findings indicate that NMDAR-LTD is required for consolidation, but not the acquisition of fear memory. Our study also shows that Bax plays an important role in depressive behavior. PMID:24966374
Liu, Xing; Gu, Qin-Hua; Duan, Kaizheng; Li, Zheng
Long-Term Planning in Higher Education.
This report presents the concepts and issues discussed at a Regional Symposium on Long-term Planning in Higher Education held in Dhaka, Bangladesh, September 21-30, 1986. Chapter 1 explores some fundamental issues about the rationale for the objectives of long-term planning. It defines long-term planning in higher education, considers its�
United Nations Educational, Scientific and Cultural Organization, Bangkok (Thailand). Principal Regional Office for Asia and the Pacific.
Chronic ceftriaxone treatment rescues hippocampal memory deficit in AQP4 knockout mice via activation of GLT-1.
Aquaporin-4 (AQP4) is the predominant water channel protein in the mammalian brain, and is mainly expressed in astrocytes. Besides its important role in water transport across the blood-brain barrier, our present study demonstrated that AQP4 deficiency impaired hippocampal long-term potentiation (LTP) and hippocampus-dependent memory formation, accompanied by the increase in extracellular glutamate concentration and N-methyl-d-aspartate (NMDA) receptor-mediated currents in hippocampal dentate gyrus (DG) region. The impairment of LTP and memory formation of AQP4 knockout (KO) mice was mediated by the downregulation of glutamate transporter-1 (GLT-1) expression/function, since it can be rescued by ?-lactam antibiotic ceftriaxone (Cef), a potent GLT-1 stimulator. These results suggest that AQP4 functions as the modulator of synaptic plasticity and memory, and chronic Cef treatment rescues hippocampal memory deficit induced by AQP4 knockout. PMID:23973312
Yang, Jun; Li, Ming-Xing; Luo, Yi; Chen, Tao; Liu, Jing; Fang, Peng; Jiang, Bo; Hu, Zhuang-Li; Jin, You; Chen, Jian-Guo; Wang, Fang
A Specific Role for Group I mGluRs in Hippocampal LTP and Hippocampus-Dependent Spatial Learning
Digital Repository Infrastructure Vision for European Research (DRIVER)
Metabotropic glutamate receptors (mGluRs) have been implicated in long-term potentiation and in learning and memory formation. In this study, we tested the effects of group I mGluR inhibition on synaptic plasticity and learning of rats at different levels of organization (1) in the hippocampal slice preparation; (2) in freely moving animals implanted with chronic hippocampal electrodes; and (3) in different spatial learning paradigms. To allow a direct comparison of the effects obtained the s...
Balschun, Detlef; Manahan-vaughan, Denise; Wagner, Thomas; Behnisch, Thomas; Reymann, Klaus G.; Wetzel, Wolfram
Physiological, Molecular and Genetic Mechanisms of Long-Term Habituation
Energy Technology Data Exchange (ETDEWEB)
Work funded on this grant has explored the mechanisms of long-term habituation, a ubiquitous form of learning that plays a key role in basic cognitive functioning. Specifically, behavioral, physiological, and molecular mechanisms of habituation have been explored using a simple model system, the tail-elicited siphon-withdrawal reflex (T-SWR) in the marine mollusk Aplysia californica. Substantial progress has been made on the first and third aims, providing some fundamental insights into the mechanisms by which memories are stored. We have characterized the physiological correlates of short- and long-term habituation. We found that short-term habituation is accompanied by a robust sensory adaptation, whereas long-term habituation is accompanied by alterations in sensory and interneuron synaptic efficacy. Thus, our data indicates memories can be shifted between different sites in a neural network as they are consolidated from short to long term. At the molecular level, we have accomplished microarray analysis comparing gene expression in both habituated and control ganglia. We have identified a network of putatively regulated transcripts that seems particularly targeted towards synaptic changes (e.g. SNAP25, calmodulin) . We are now beginning additional work to confirm regulation of these transcripts and build a more detailed understanding of the cascade of molecular events leading to the permanent storage of long-term memories. On the third aim, we have fostered a nascent neuroscience program via a variety of successful initiatives. We have funded over 11 undergraduate neuroscience scholars, several of whom have been recognized at national and regional levels for their research. We have also conducted a pioneering summer research program for community college students which is helping enhance access of underrepresented groups to life science careers. Despite minimal progress on the second aim, this project has provided a) novel insight into the network mechanisms by which short-term memories are permanently stored, and b) a strong foundation for continued growth of an excellent undergraduate neuroscience program.
Calin-Jageman, Robert J
Digital Repository Infrastructure Vision for European Research (DRIVER)
Impairment of memory functions has been frequently reported in models of sleep deprivation. Similarly, hippocampal long-term synaptic plasticity has been shown to be sensitive to sleep loss due to acute sleep restriction. However, such approaches are limited by the stressful nature of sleep deprivation, and because it is difficult to study long term sleep restriction in animals. Here we report the effects of chronic sleep loss on hippocampal long-term potentiation (LTP) in a rodent model for ...
Arrigoni, Elda; Lu, Jun; Vetrivelan, Ramalingam; Saper, Clifford B.
Dendritic spikes induce single-burst long-term potentiation
Digital Repository Infrastructure Vision for European Research (DRIVER)
The hippocampus is essential for episodic memory, which requires single-trial learning. Although long-term potentiation (LTP) of synaptic strength is a candidate mechanism for learning, it is typically induced by using repeated synaptic activation to produce precisely timed, high-frequency, or rhythmic firing. Here we show that hippocampal synapses potentiate robustly in response to strong activation by a single burst. The induction mechanism of this single-burst LTP requires activation of NM...
Remy, Stefan; Spruston, Nelson
Diversity in Long-Term Synaptic Plasticity at Inhibitory Synapses of Striatal Spiny Neurons
Procedural memories and habits are posited to be stored in the basal ganglia, whose intrinsic circuitries possess important inhibitory connections arising from striatal spiny neurons. However, no information about long-term plasticity at these synapses is available. Therefore, this work describes a novel postsynaptically dependent long-term�
Rueda-Orozco, Pavel E.; Mendoza, Ernesto; Hernandez, Ricardo; Aceves, Jose J.; Ibanez-Sandoval, Osvaldo; Galarraga, Elvira; Bargas, Jose
Long Term Preservation of Digital Information.
The preservation of digital data for the long term presents a variety of challenges from technical to social and organizational. The technical challenge is to ensure that the information, generated today, can survive long term changes in storage media, devices, and data formats. This paper presents a novel approach to the problem. It distinguishes�
Lorie, Raymond A.
Long-Term Care Ombudsman Program
... training sessions in facilities on such topics as residents� rights. Provided 114,033 consultations to long-term care ... Agencies to provide information and options counseling to residents. In addition, AoA and CMS are encouraging States to coordinate with State Long-Term Care Ombudsman ...
Cell and molecular analysis of long-term sensitization in Aplysia
Digital Repository Infrastructure Vision for European Research (DRIVER)
We have found that one cellular locus for the storage of the memory underlying short-term sensitization of the gill and siphon withdrawal reflex in Aplysia is the set of monosynaptic connections between the siphon sensory cells and the gill and siphon motor neurons. These connections also participate in the storage of memory underlying long-term sensitization. In animals that have undergone long-term sensitization, the amplitudes of the monosynaptic connections are significantly larger (2.2x)...
Montarolo, Pier Giorgio
Type 1 Adenylyl Cyclase is Essential for Maintenance of Remote Contextual Fear Memory
Digital Repository Infrastructure Vision for European Research (DRIVER)
Although molecular mechanisms for hippocampus-dependent memory have been extensively studied, much less is known about signaling events important for remote memory. Here we report that mice lacking type 1 adenylyl cyclase (AC1) are able to establish and retrieve remote contextual memory but unable to sustain it as long as wild type mice. Interestingly, mice over-expressing AC1 show superior remote contextual memory even though they exhibit normal hippocampus-dependent contextual memory. These...
Shan, Qiang; Chan, Guy C. -k; Storm, Daniel R.
Long term wet spent nuclear fuel storage
International Nuclear Information System (INIS)
The meeting showed that there is continuing confidence in the use of wet storage for spent nuclear fuel and that long-term wet storage of fuel clad in zirconium alloys can be readily achieved. The importance of maintaining good water chemistry has been identified. The long-term wet storage behaviour of sensitized stainless steel clad fuel involves, as yet, some uncertainties. However, great reliance will be placed on long-term wet storage of spent fuel into the future. The following topics were treated to some extent: Oxidation of the external surface of fuel clad, rod consolidation, radiation protection, optimum methods of treating spent fuel storage water, physical radiation effects, and the behaviour of spent fuel assemblies of long-term wet storage conditions. A number of papers on national experience are included
Long term effects of radiation in man
Energy Technology Data Exchange (ETDEWEB)
An overview of the long term effects of radiation in man is presented, categorizing into somatic effects, genetic effects and teratogenic effects, and including an indication of the problems that arise in their determination.
Tso Chih Ping (Malaya Univ., Kuala Lumpur (Malaysia)); Idris Besar (PUSPATI, Selangor (Malaysia))
Long-term Treatment of Venous Thromboembolism.
Long term treatment of venous thromboembolism is essential to complete therapy of the index episode and to reduce recurrences. Vitamin K antagonists are the mainstay for the long term treatment of venous thromboembolism for the majority of the patients as they allow oral administration. Low-molecular weight heparins are recommended for the long term treatment of cancer patients. The duration of long term anticoagulation depends on the features of the index venous thromboembolism and on the presence of associated risk factors. Patients at high risk for recurrence - mainly those who suffered unprovoked venous thromboembolism and those with cancer - should be evaluated for extended anticoagulation. The risk for major bleeding complications and the inconvenience for monitoring, dose adjustment and drug-food interactions are the main constraints for indefinite anticoagulant treatment. New anticoagulants with more favourable efficacy- safety profile and reduced need for monitoring could improve the feasibility of extended anticoagulation. PMID:24846227
Becattini, Cecilia; Manina, Giorgia
Long term liquidity analysis of the firm
Directory of Open Access Journals (Sweden)
Full Text Available Liquidity control is a very difficult and important function. If the business is not liquid in the long term, it is under threatof bankruptcy, and on the other hand surplus of the cash in hand threaten its future efficiency, because the cash in hand is a sourceof only limited profitability. Long term liquidity is related to the ability of the short term and long term liabilities payment. Articleis trying to point out to the monitoring and analyzing of the long term liquidity in the concrete business, in this case the printing industrycompany. Hereby at the end of the article mentioned monitored and analyzed liquidity is evaluated in the five years time period.
Jaroslav Gonos
Deferred tax and long-term insurers
Digital Repository Infrastructure Vision for European Research (DRIVER)
Focuses on the new AC 102 on Income Taxes, which was issued in March 1999. Discusses several new issues regarding the provision of deferred tax that arose for enterprises in general and for long-term insurers in particular.
Stiglingh, M.; Koornhof, Carolina
The Lithuanian Long-term Care System
Digital Repository Infrastructure Vision for European Research (DRIVER)
The remarkable growth of older population has moved long-term care to the front ranks of the social policy agenda in the European Union. This paper addresses the issue of the longterm care in Lithuania, its philosophy, the legal and funding regularities, management issues and LTC policy. Its attempt is also to provide a complex set of information about the demand side of long-term care including the demographic characteristics of people in need. The paper also presents a detailed description ...
Exchange rates and long-term bonds
Digital Repository Infrastructure Vision for European Research (DRIVER)
Tentative evidence suggests that the empiricalfailure of uncovered interest parity (UIP) is confined to short-term interest rates. Tests of UIP for long-term interest rates are however hampered by various data problems. By focusing on short investments in long-term bonds, these data problems can be avoided. We study the relationship between the US dollar - Deutsch Mark exchange rate and German and American bond rates. The hypothesis that expected returns to investments in bonds denominated in...
Alexius, Annika; Sellin, Peter
Exchange rates and long-term bonds
Digital Repository Infrastructure Vision for European Research (DRIVER)
Tentative evidence suggests that the empirical failure of uncovered interest parity (UIP) is confined to short-term interest rates. Tests of UIP for long-term interest rates are however hampered by various data problems. By focusing on short investments in long-term bonds, these data problems can be avoided. We study the relationship between the US dollar - Deutsch Mark exchange rate and German and American bond rates. The hypothesis that expected returns to investments in bonds denominated i...
Alexius, Annika; Sellin, Peter
Digital Repository Infrastructure Vision for European Research (DRIVER)
With expansion of e-business and consequently with creating original electronic documents, legally compliant long-term digital preservation has become a commitment for organizations that do business electronically. Accepted legislation that equalizes the legal validity of electronic documents with their paper original, regulates the operating and preservation of documents, recommendations, existing standards and service and equipment providers for ensuring long-term digital preservation, enab...
Toward a comprehensive long term nicotine policy
Digital Repository Infrastructure Vision for European Research (DRIVER)
Global tobacco deaths are high and rising. Tobacco use is primarily driven by nicotine addiction. Overall tobacco control policy is relatively well agreed upon but a long term nicotine policy has been less well considered and requires further debate. Reaching consensus is important because a nicotine policy is integral to the target of reducing tobacco caused disease, and the contentious issues need to be resolved before the necessary political changes can be sought. A long term and comprehen...
Gray, N.; Henningfield, J.; Benowitz, N.; Connolly, G.; Dresler, C.; Fagerstrom, K.; Jarvis, M.; Boyle, P.
Long-term outcomes of esophageal atresia
Digital Repository Infrastructure Vision for European Research (DRIVER)
Esophageal atresia (EA), a common congenital anomaly comprising interrupted esophagus with or without a tracheoesophageal fistula (TEF), affects one in 2840 newborns. Over half have associated anomalies. After EA repair in infancy, gastroesophageal reflux (GER) and esophageal dysmotility and respiratory problems are common. As there exist no previous population-based long-term follow-up-studies on EA, its long-term sequelae are unclear. The aims of this study were to assess the cancer inciden...
Sistonen, Saara
Long-Term Use of Benzodiazepines
Problems associated with physical dependence and abuse of benzodiazepines by a small percentage of patients have reduced their popularity from the most commonly prescribed psychoactive drug in the 1970s to being prescribed for mainly short periods. Patients who benefit from long-term benzodiazepine use are nearly ignored by the medical community as a whole. This article details what patient population can improve from long-term benzodiazepine therapy, the risks and benefits of treatment, and how to select appropriate candidates.
Potts, Nicholas L.S.; Krishnan, K. Ranga R.
Long-term survival after perforated diverticulitis
Digital Repository Infrastructure Vision for European Research (DRIVER)
Aim: Short-term survival after emergency surgery for perforated diverticulitis is poor. Less is known about long-term survival. The aims of this study were to evaluate long-term survival after discharge from hospital and to identify factors associated with prognosis. Method: All patients who underwent emergency surgery for perforated diverticulitis in five hospitals in Rotterdam, the Netherlands, between 1990 and 2005, were included. The association between type of surgery (Hartmann's procedu...
Vermeulen, J.; Gosselink, M. P.; Hop, W. C. J.; Harst, E.; Hansen, B. E.; Mannaerts, G. H. H.; Coene, P-p; Weidema, W. F.; Lange, J. F.
Long term vision of power generation
International Nuclear Information System (INIS)
A long-term vision of power generation leads us to the conclusion that future generation will be dominated by those technologies capable of facing the challenge of reducing greenhouse effect gas emissions without neglecting other core objectives envisaged in the energy policy, i.e. supply security and competitiveness. For this reason, sustainable utilities must foster different energies in the short, medium and long term.Given the investments required by these generation technologies, power companies will need huge financial resources. (Author)
Long-Term Opioid Therapy Reconsidered
Digital Repository Infrastructure Vision for European Research (DRIVER)
In the past 20 years, primary care physicians have greatly increased prescribing of long-term opioid therapy. However, the rise in opioid prescribing has outpaced the evidence regarding this practice. Increased opioid availability has been accompanied by an epidemic of opioid abuse and overdose. The rate of opioid addiction among patients receiving long-term opioid therapy remains unclear, but research suggests that opioid misuse is not rare. Recent studies report increased risks for serious ...
Foreign Currency for Long-Term Investors
Digital Repository Infrastructure Vision for European Research (DRIVER)
Conventional wisdom holds that conservative investors should avoid exposure to foreign currency risk. Even if they hold foreign equities, they should hedge the currency exposure of these positions and hold only domestic Treasury bills. This paper argues that the conventional wisdom may be wrong for long-term investors. Domestic bills are risky for long-term investors, because real interest rates vary over time and bills must be rolled over at uncertain future interest rates. This risk can be ...
Viceira, Luis; Campbell, John; White, Joshua
Enhanced hippocampal long-term potentiation and spatial learning in aged 11�-hydroxysteroid dehydrogenase type 1 knock-out mice
Digital Repository Infrastructure Vision for European Research (DRIVER)
Glucocorticoids are pivotal in the maintenance of memory and cognitive functions as well as other essential physiological processes including energy metabolism, stress responses, and cell proliferation. Normal aging in both rodents and humans is often characterized by elevated glucocorticoid levels that correlate with hippocampus-dependent memory impairments. 11�-Hydroxysteroid dehydrogenase type 1 (11�-HSD1) amplifies local intracellular ("intracrine") glucocorticoid action; in the brain i...
Yau, J. L. W.; Mcnair, K. M.; Noble, J.; Brownstein, D.; Hibberd, C.; Morton, N.; Mullins, J. J.; Morris, R. G. M.; Cobb, S.; Seckl, J. R.
Long-term synaptic plasticity in hippocampal interneurons.
Rapid memory formation relies, at least in part, on long-term potentiation (LTP) of excitatory synapses. Inhibitory interneurons of the hippocampus, which are essential for information processing, have recently been found to exhibit not one, but two forms of LTP. One form resembles LTP that occurs in pyramidal neurons, which depends on N-methyl-D-aspartate receptors and is triggered by coincident pre- and postsynaptic activity. The other depends on Ca2+ influx through glutamate receptors that preferentially open when the postsynaptic neuron is at rest. Here we review these contrasting forms of LTP and describe how they are mirrored by two forms of long-term depression. We further discuss how the remarkable plasticity of glutamatergic synapses on interneurons greatly enhances the computational capacity of the cortical microcircuit. PMID:17704811
Kullmann, Dimitri M; Lamsa, Karri P
Long-term follow-up study and long-term care of childhood cancer survivors
Directory of Open Access Journals (Sweden)
Full Text Available The number of long-term survivors is increasing in the western countries due to remarkable improvements in the treatment of childhood cancer. The long-term complications of childhood cancer survivors in these countries were brought to light by the childhood cancer survivor studies. In Korea, the 5-year survival rate of childhood cancer patients is approaching 70%; therefore, it is extremely important to undertake similar long-term follow-up studies and comprehensive long-term care for our population. On the basis of the experiences of childhood cancer survivorship care of the western countries and the current Korean status of childhood cancer survivors, long-term follow-up study and long-term care systems need to be established in Korea in the near future. This system might contribute to the improvement of the quality of life of childhood cancer survivors through effective intervention strategies.
Hyeon Jin Park
Dysfunction of the RAR/RXR signaling pathway in the forebrain impairs hippocampal memory and synaptic plasticity
Directory of Open Access Journals (Sweden)
Full Text Available Abstract Background Retinoid signaling pathways mediated by retinoic acid receptor (RAR/retinoid � receptor (RXR-mediated transcription play critical roles in hippocampal synaptic plasticity. Furthermore, recent studies have shown that treatment with retinoic acid alleviates age-related deficits in hippocampal long-term potentiation (LTP and memory performance and, furthermore, memory deficits in a transgenic mouse model of Alzheimer's disease. However, the roles of the RAR/RXR signaling pathway in learning and memory at the behavioral level have still not been well characterized in the adult brain. We here show essential roles for RAR/RXR in hippocampus-dependent learning and memory. In the current study, we generated transgenic mice in which the expression of dominant-negative RAR (dnRAR could be induced in the mature brain using a tetracycline-dependent transcription factor and examined the effects of RAR/RXR loss. Results The expression of dnRAR in the forebrain down-regulated the expression of RAR?, a target gene of RAR/RXR, indicating that dnRAR mice exhibit dysfunction of the RAR/RXR signaling pathway. Similar with previous findings, dnRAR mice displayed impaired LTP and AMPA-mediated synaptic transmission in the hippocampus. More importantly, these mutant mice displayed impaired hippocampus-dependent social recognition and spatial memory. However, these deficits of LTP and memory performance were rescued by stronger conditioning stimulation and spaced training, respectively. Finally, we found that pharmacological blockade of RAR? in the hippocampus impairs social recognition memory. Conclusions From these observations, we concluded that the RAR/RXR signaling pathway greatly contributes to learning and memory, and LTP in the hippocampus in the adult brain.
Nomoto Masanori
The effect of long-term high frequency repetitive transcranial magnetic stimulation on working memory in schizophrenia and healthy controls--a randomized placebo-controlled, double-blind fMRI study.
In schizophrenia patients negative symptoms and cognitive impairment often persist despite treatment with second generation antipsychotics leading to reduced quality of life and psychosocial functioning. One core cognitive deficit is impaired working memory (WM) suggesting malfunctioning of the dorsolateral prefrontal cortex. High frequency repetitive transcranial magnetic stimulation (rTMS) has been used to transiently facilitate or consolidate neuronal processes. Pilot studies using rTMS have demonstrated improvement of psychopathology in other psychiatric disorders, but a systematic investigation of working memory effects outlasting the stimulation procedure has not been performed so far. The aim of our study was to explore the effect of a 3-week high frequency active or sham 10 Hz rTMS on cognition, specifically on working memory, in schizophrenia patients (n=25) in addition to antipsychotic therapy and in healthy controls (n=22). We used functional magnetic resonance imaging (fMRI) to compare activation patterns during verbal WM (letter 2-back task) before and after 3-weeks treatment with rTMS. Additionally, other cognitive tasks were conducted. 10 Hz rTMS was applied over the left posterior middle frontal gyrus (EEG electrode location F3) with an intensity of 110% of the individual resting motor threshold (RMT) over a total of 15 sessions. Participants recruited the common fronto- parietal and subcortical WM network. Multiple regression analyses revealed no significant activation differences over time in any contrast or sample. According to the ANOVAs for repeated measures performance remained without alterations in all groups. This is the first fMRI study that has systematically investigated this topic within a randomized, placebo-controlled, double-blind design, contrasting the effects in schizophrenia patients and healthy controls. PMID:23022750
Guse, Birgit; Falkai, Peter; Gruber, Oliver; Whalley, Heather; Gibson, Lydia; Hasan, Alkomiet; Obst, Katrin; Dechent, Peter; McIntosh, Andrew; Suchan, Boris; Wobrock, Thomas
Long-term changes in Saturn's troposphere
International Nuclear Information System (INIS)
Attention is given to the results of a long term monitoring study of Saturn's H_2 quadrupole and CH_4 band absorptions outside the equatorial zone, over an interval of half a Saturn year that covers most of the perihelion half of Saturn's elliptical orbit (which is approximately bounded by the equinoxes). Marked long term changes are noted in the CH_4 absorption, accompanied by weakly opposite changes in the H_2 absorption. Seasonal changes are inferred on the basis of temporal variations in absorption. Spatial measurements have also been made in the 6450 A NH_3 band since the 1980 equinox. 42 references
Long-term effects of forced migration
Digital Repository Infrastructure Vision for European Research (DRIVER)
We study the long-term effects of human displacement using individual level panel data on forced migrants and comparable non-migrants. After World War II, Finland ceded a tenth of its territory to the Soviet Union and resettled the entire population living in these areas in the remaining parts of the country. We find that displacement increased the long-term income of men, but had no effect on that of women. We attribute a large part of the effect to faster transition from traditional (rural)...
Long-term effects of forced migration
Digital Repository Infrastructure Vision for European Research (DRIVER)
We study the long-term effects of human displacement using individual-level panel data on forced migrants and comparable non-migrants. After World War II, Finland ceded a tenth of its territory to the Soviet Union and resettled the entire population living in these areas in the remaining parts of the country. We find that displacement increased the long-term income of men, but had no effect on that of women. We attribute a large part of the effect to faster transition from traditional (rural)...
Long Term Changes in Marine Fisheries
This Issue focuses on a research article by Barange (2003) that was published in Frontiers in Ecology and the Environment. The article discusses long-term (inter-decadal and longer) patterns of change in marine species in the context of over-exploitation of marine fisheries. Barange��s emphasis is use of ecosystem-based management practice to move us towards sustainable fisheries. However, he questions whether we know enough about patterns and causes of long term change in marine ecosystems to develop such practices.
D'Avanzo, Charlene
Forecasting long-term load growth uncertainty
Energy Technology Data Exchange (ETDEWEB)
This paper presents the methodology and results developed and used by Ontario Hydro, the largest electric utility in North America, to forecast its long-term load growth uncertainty. An econometric methodology for forecasting long-term demand for electricity is developed and two varibale elasticity models (VEM) are estimated empirically. Simulation procedures of applying these models to quantify uncertainty (described in propability distributions) associated with furute energy demand growth are also developed and results are reported. The VEM and simulation techniques are believed to be relatively new in energy forecasting and planning. (author) 59 refs.
Keng, C.W.K. (Economics and Forecasts Divison, Ontario Hydro, Toronto, Ontario (CA))
Long-term Video-EEG Monitoring for Paroxysmal Events
Directory of Open Access Journals (Sweden)
Full Text Available Background: Long term video-electroencephalography monitoring (VEM has been widelyused for the diagnosis, classification, and management of seizures. Fewstudies have systemically examined its safety issues and clinical utility. Thisprospective study investigates the general clinical application of long termVEM in the management of paroxysmal events.Methods: This study cohort consisted of patients admitted to the inpatient VEM unit atChang Gung Memorial Hospital (Lin-Kou. Standard 19 channel scalp electroencephalography(EEG, electrocardiography (ECG, and simultaneousvideo images were recorded continuously for 2 full days. Patient characteristics,and clinical, video-EEG and safety data were obtained and analyzed.The diagnosis and management of paroxysmal events before VEM werecompared with those after VEM.Results: Habitual events were recorded in 54.3% of the 129 patients, and VEM had ayield rate of 76% (events recorded or newly recorded interictal discharges indetermining the nature of the events. Eleven patients had seizure clusters, butthere was no status epilepticus or electrode-related injury. After VEM, thediagnostic categories were changed in 41.1% of the patients, and 40.3% hadrevisions in management.Conclusions: Long term VEM is a safe diagnostic tool providing a high diagnostic yieldrate and directing adjustment of management for patients with paroxysmalevents.
Ying-Ying Lee
Foundation work in long-term care.
Health foundations have invested in services, research, and advocacy to improve the financing and delivery of long-term services and supports. This article describes some of the broad array of approaches they have taken--in such areas as aging in place, assisted living, "culture change" in nursing homes, quality improvement, augmenting the workforce, and paying for care. PMID:20048379
LeRoy, Lauren; Treanor, Katherine; Art, Emily
Strategic long term planning in mining
Scientific Electronic Library Online (English)
Full Text Available SciELO South Africa | Language: English Abstract in english The fundamental challenge facing mineral and metal companies is how to create sustainable value while operating within mandated strategic bounds, identified constraints, and variable market and economic conditions. This can be achieved by allowing the fixed physical nature of the mineral asset to dr [...] ive definition of the optimal technical solution to mining and processing activities, and developing and resourcing a strategically aligned portfolio of production entities that creates flexibility to near- and longer-term business environment shifts, i.e. a production mix that allows variation of output to respond to short term market variation, within a long term context. The practical achievement of this outcome is enabled by the concept of strategic long term planning. The core elements of strategic long term planning in the metals and minerals industry, and the relationship between them, are expanded. The strategic long term planning framework is a logic construct that enables delivery of an optimized, strategically-aligned business plan from the mineral asset portfolio using a set of tools and techniques with a common language, standards, systems and processes to align decisions and actions on a cyclical basis.
G.L., Smith.
Long-Term Impacts of Educational Interventions
The school accountability movement has led to a marked increase in the use of standardized test scores to measure school and teacher productivity, yet little is known about the correlation between test score gains and improvements in long-term outcomes. In the first chapter of my dissertation, I study the impact of a school choice policy in�
Deming, David James
Long term planning: North Norfolk coast
�managing each section of the coast over the short term (up to 20 years), medium term (20-50 years) and long term (50-100 years). These new plans consider a range of factors, such as sea level rise. The new SMPs work with natural coastal processes and reduce the reliance on built coastal defences. 'The communities�
Long-term behavior of bituminized waste
International Nuclear Information System (INIS)
The long-term properties of bituminized ion exchange resins were studied in a repository environment with access of water equilibrated with concrete. In these circumstances the most important properties are related to the interactions of bituminized waste with the surrounding barriers. The most important phenomena are water uptake due to rehydration of the resins and subsequent swelling of the product
... for incontinence Eating Other common long-term care services and supports are assistance with everyday tasks , sometimes called Instrumental Activities of Daily Living (IADLs) including: Housework Managing money Taking medication Preparing and cleaning up after meals Shopping for groceries or clothes ...
Bidding for Long-Term Care Patients.
This document outlines options for a long-term care system in which competitive bidding is used to establish the price of care. The design of the competitive bidding mechanism is examined along with the interaction and cross-impact of competitive bidding ...
A. J. Hogan C. V. Getts
Improving students' long-term knowledge retention through personalized review.
Human memory is imperfect; thus, periodic review is required for the long-term preservation of knowledge and skills. However, students at every educational level are challenged by an ever-growing amount of material to review and an ongoing imperative to master new material. We developed a method for efficient, systematic, personalized review that combines statistical techniques for inferring individual differences with a psychological theory of memory. The method was integrated into a semester-long middle-school foreign-language course via retrieval-practice software. Using a cumulative exam administered after the semester's end, we compared time-matched review strategies and found that personalized review yielded a 16.5% boost in course retention over current educational practice (massed study) and a 10.0% improvement over a one-size-fits-all strategy for spaced study. PMID:24444515
Lindsey, Robert V; Shroyer, Jeffery D; Pashler, Harold; Mozer, Michael C
Long-term results after pancreas transplantation.
With the advances in technique and immunosupression, not only the short- but the long-term outcomes of pancreas transplantation have improved significantly. This retrospective study describes the long-term outcomes of simultaneous pancreas and kidney (SPK) transplants, pancreas after kidney (PAK), and pancreas transplants alone (PTA). An overall analysis was performed for all deceased donor (DD) primary pancreas transplants performed in the United States between 1988 and 1999. In addition, the long-term outcome for pancreas transplants performed at the University of Minnesota (UM) was analyzed. For SPK transplants performed in the United States between 1998 and 1999, the half-life of the pancreas was almost 12 years, and was 12.5 years for kidneys. For SPK cases where the pancreas was functioning at 1 year, the half-lives of both the pancreas and the kidney grafts extended more than 14 years. The half-lives of solitary pancreas transplants were between 7 years for PAK and 9 years for PTA cases. For US solitary transplants with at least 1 year of graft function, the half-lives extended to almost 9 years. Pancreas transplants performed at the UM showed the same significant improvements over time. Of special interest is the excellent long-term graft function of pancreas transplants from a living donor, which in the early years clearly surpassed that of solitary DD pancreas transplants. A multivariate analysis showed that the factor with the highest impact on long-term graft function in all three transplant categories was the use of a young donor. In SPK cases, the most frequent reason for late graft loss was death with a functioning graft. In solitary pancreas transplants, most late graft losses were still due to immunological reasons. PMID:17889177
Sutherland, D E R; Gruessner, A C
[Long-term results in pediatric orthopedics].
Whether to treat deformities in childhood or even to operate on them is a difficult decision which may affect a patient's whole life. Most important is a sound knowledge of the natural course. Many 'deformities' are just normal variants, and others improve during the growth period, but some get worse and may cause damage in later life. However the outcome of operations is not always certain. Recurrence may occur as well as overcorrection; therefore, the long-term prognosis, with or without treatment, must be the guideline for indications. If an operation is considered, timing and extent of a correction are decisive. On the grounds of long-term outcome studies, guidelines can be established for the treatment of different diseases and deformities: upper extremities [dysmelia, elbow], spine [scoliosis, Scheuermann's disease, spondylolisthesis], hip (congenital dysplasia, Perthes' disease, slipped epiphysis), knee and feet (flatfoot, pes equinovarus). PMID:7631274
Engelhardt, P
Consequences of long-term hyperparathyroidism.
We describe a young woman with long-term untreated hyperparathyroidism with a superimposed vitamin D deficiency and an extremely decreased bone mineral density that was complicated by a vertebral fracture. Despite pretreatment with intravenous pamidronate and short-term vitamin D supplementation, severe and long-standing hypocalcaemia ('hungry bone syndrome') developed after parathyroidectomy. We discuss the consequences of hyperparathyroidism, especially the effects on bone, the complications of parathyroidectomy and the possibilities of preoperative treatment with bisphosphonates. PMID:9718941
Graal, M B; Wolffenbuttel, B H
Long-Term Care, Altruism and Socialization
Digital Repository Infrastructure Vision for European Research (DRIVER)
The public provision of long-term care (LTC) can replace family-provided LTC when adults are not sufficiently altruistic towards their elderly parents. But State intervention can also modify the transmission of values and reduce the long-run prevalence of family altruism in the population. That evolutionary effect questions the desirability of the LTC public provision. To characterize the optimal LTC policy, we develop a three-period OLG model where the population is divided into altruistic a...
Long-term participation tax rates
Digital Repository Infrastructure Vision for European Research (DRIVER)
Generous income support programs as provided by European welfare states have often been blamed to reduce work incentives for the lowskilled and to increase durations of unemployment. Standard studies measure work incentives based on annual income concepts. This paper analyzes work incentives inherent in the German tax-benefit system when extending the time horizon to three years (long-term). Participation tax rates are computed for 1-year and 3-year periods 1995-1997 and 2005-2007 to reveal p...
Bartels, Charlotte
Long-term consequences of anorexia nervosa.
Anorexia nervosa (AN) is a psychiatric disorder that occurs mainly in female adolescents and young women. The obsessive fear of weight gain, critically limited food intake and neuroendocrine aberrations characteristic of AN have both short- and long-term consequences for the reproductive, cardiovascular, gastrointestinal and skeletal systems. Neuroendocrine changes include impairment of gonadotropin releasing-hormone (GnRH) pulsatile secretion and changes in neuropeptide activity at the hypothalamic level, which cause profound hypoestrogenism. AN is related to a decrease in bone mass density, which can lead to osteopenia and osteoporosis and a significant increase in fracture risk in later life. Rates of birth complications and low birth weight may be higher in women with previous AN. The condition is associated with fertility problems, unplanned pregnancies and generally negative attitudes to pregnancy. During pregnancy, women with the condition have higher rates of hyperemesis gravidarum, anaemia and obstetric complications, as well as impaired weight gain and compromised intrauterine foetal growth. It is reported that 80% of AN patients are affected by a cardiac complications such as sinus bradycardia, a prolonged QT interval on electrocardiography, arrythmias, myocardial mass modification and hypotension. A decrease in bone mineral density (BMD) is one of the most important medical consequences of AN. Reduced BMD may subsequently lead to a three- to seven-fold increased risk of spontaneous fractures. Untreated AN is associated with a significant increase in the risk of death. Better detection and sophisticated therapy should prevent the long-term consequences of this disorder. The aims of treatment are not only recovery but also prophylaxis and relief of the long-term effects of this disorder. Further investigations of the long-term disease risk are needed. PMID:23706279
Meczekalski, Blazej; Podfigurna-Stopa, Agnieszka; Katulski, Krzysztof
Long-term reductions in tinnitus severity
Digital Repository Infrastructure Vision for European Research (DRIVER)
Abstract Background This study was undertaken to assess long-term changes in tinnitus severity exhibited by patients who completed a comprehensive tinnitus management program; to identify factors that contributed to changes in tinnitus severity within this population; to contribute to the development and refinement of effective assessment and management procedures for tinnitus. Methods Detailed questionnaires were mailed to 300 consecutive patients prior to thei...
Dynamics of long-term statin therapy
Digital Repository Infrastructure Vision for European Research (DRIVER)
Abstract Purpose Knowledge of the different usage patterns that emerge during a long-term statin therapy is limited. The aim of this study was to characterize statin use, including the rates of reinitiation after extended periods of non-use, transitions between good and poor adherence, and the effect of the length of a drug-free period on the identification of new users. Methods The study cohort comprised ...
Bacterial cellulose : long-term biocompatibility studies
Digital Repository Infrastructure Vision for European Research (DRIVER)
The bacterial cellulose (BC) secreted by G. xylinus is a network of pure cellulose nanofibers, which has high crystallinity, wettability and mechanical strength. These characteristics make BC an excellent material for tissue engineering constructs, noteworthy for artificial vascular grafts. In this work, the in vivo biocompatibility of BC membranes produced by two G. xylinus strains was analyzed through histological analysis of long-term subcutaneous implants in the mice. The BC implants caus...
Pe?rtile, Renata Aparecida Nedel; Moreira, Susana; Costa, Rui M. Gil Da; Correia, Alexandra; Guarda?o, Lui?sa; Gartner, Fa?tima; Vilanova, Manuel; Gama, F. M.
Long-term outlook for electric demand
Energy Technology Data Exchange (ETDEWEB)
Utilities are showing more willingness to let lower demand forecasts reflect unfavorable economic conditions, but they may now be overreacting to short-term situations. Long-term growth estimates based on demand estimates of real rates and real gross national product (GNP) suggest a demand growth of 4.5 and 5% per year, given a 3% growth in real GNP and a 2% growth in electric rates, and not the 2.5% estimated by the utility industry. (DCK)
Studness, C.M.
Social long term care insurance and redistribution
Digital Repository Infrastructure Vision for European Research (DRIVER)
We study the role of social long term care (LTC) insurance when income taxation and private insurance markets are imperfect. Policy instruments include public provision of LTC as well as a subsidy on private insurance. The subsidy scheme may be linear or nonlinear. For the linear part we consider a continuous distribution of types, characterized by earnings and survival probabilities. In the nonlinear part, society consists of three types: poor, middle class and rich. The first type is too po...
Cremer, Helmuth; Pestieau, Pierre
Clinical review: Long-term noninvasive ventilation
Digital Repository Infrastructure Vision for European Research (DRIVER)
Noninvasive positive ventilation has undergone a remarkable evolution over the past decades and is assuming an important role in the management of both acute and chronic respiratory failure. Long-term ventilatory support should be considered a standard of care to treat selected patients following an intensive care unit (ICU) stay. In this setting, appropriate use of noninvasive ventilation can be expected to improve patient outcomes, reduce ICU admission, enhance patient comfort, and increase...
Robert, Dominique; Argaud, Laurent
Cutaneous oxalosis after long-term hemodialysis.
A 27-year-old woman undergoing long-term hemodialysis developed cutaneous calcifications on her fingers. A skin biopsy specimen showed that the deposits were calcium oxalate. To our knowledge, only one previous article has reported pathologic and crystallographic studies on calcifications of the skin resulting from dialysis oxalosis. We speculate that vitamin C supplements, liberal tea consumption, an increased serum ionized calcium concentration, and the long duration of hemodialysis contributed to the production of these deposits. PMID:1627032
Abuelo, J G; Schwartz, S T; Reginato, A J
Long-term outcome after respiratory rehabilitation.
Digital Repository Infrastructure Vision for European Research (DRIVER)
To determine the long-term effect of respiratory rehabilitation, we followed up for 6 months after discharge 31 consecutive patients enrolled in a multidisciplinary inpatient rehabilitation program lasting 4 to 6 weeks. Of the 31, 24 showed improvement in quality of life (as measured with a previously validated questionnaire) and in functional exercise capacity (as measured with the 6-minute walk test) 2 weeks after discharge. The improvement was sustained for 6 months in 11 of the 24. Other ...
Guyatt, G. H.; Berman, L. B.; Townsend, M.
Digital Repository Infrastructure Vision for European Research (DRIVER)
Long term load forecasting plays an important role in the economic optimization and secured operation of electric power systems. The plans of the electric power sector have been done and developed with the aid of statistical prediction methods. Electric utilities companies need monthly peak and ... 2011-01-01
Long term load forecasting plays an important role in the economic optimization and secured operation of electric power systems. The plans of the electric power sector have been done and developed with the aid of statistical prediction methods. Electric utilities companies need monthly peak and ...
Long term results of pneumatic retinopexy
Digital Repository Infrastructure Vision for European Research (DRIVER)
Amin F EllakwaMenoufiya University, Shibin el Kom, Al-Menoufiya, EgyptBackground: Rhegmatogenous retinal detachment is a commonly encountered retinal problem where rapid treatment can prevent irreversible vision loss. Pneumatic retinopexy (PR) is a simple, minimally invasive procedure for retinal reattachment.Purpose: This study aimed to assess the long-term anatomical and functional outcome of pneumatic retinopexy in primary rhegmatogenous retinal detachment.Patients and methods: A prospecti...
Af, Ellakwa
Long-term outcomes of sports injuries
Digital Repository Infrastructure Vision for European Research (DRIVER)
Participation in sports is an important way to spend spare time. Being actively involved in sports has clear advantages, like the improvement of physical endurance and the prevention of Western diseases. However, it can be questioned whether these advantages are not outweighted by the notable side effects: the occurrence and the adverse outcome of a large number of injuries. Long-term consequences are of importance in determining this outcome, since sportsmen are generally young and, conseque...
Dekker, Rienk
Urinary Diversion: long-term functional aspects.
Functional aspects and quality of life (QOL) of patients with a urinary diversion (UD) represent important issues in Urology. Any form of UD has its specific problems. In experienced hands and with regular long-term follow-up, serious complications can be avoided and excellent long-term results can be achieved. Thus, the selection of an appropriate UD is critical to patient's long-term satisfaction. Patients must be fully counseled in all types of UD and should have ready access to all options. There are 3 kinds of factors to be considered in the selection of UD: patient, physician, and general factors. In the pre-operative counseling, it is mandatory to explain all factors that over time may contribute to affect the patient's urinary tract function and QOL, mainly linked to long-term complications of UD. One of the most important requirements for any bladder substitution is that it should not jeopardize the renal function. There are many urological and non-urological potential reasons for deterioration in renal function following UD. Continence results after neobladder (NB) are difficult to compare between series published in the literature because of a lack of consensus of definitions, varied follow-up periods, and different mechanisms of data collection. In up to 22% of patients with NB, significant residual urine volumes were observed. The overall patients' QOL reported in most articles was good, irrespective of the type of UD. QOL of patients with a well functioning NB seems to be significantly better than other forms of diversion. Well-designed randomized prospective trials are warranted to render definitive conclusions. PMID:24874307
Cerruto, Maria Angela
Managing soils for long-term productivity
Digital Repository Infrastructure Vision for European Research (DRIVER)
Meeting the goal of long-term agricultural productivity requires that soil degradation be halted and reversed. Soil fertility decline is a key factor in soil degradation and is probably the major cause of declining crop yields. There is evidence that the contribution of declining soil fertility to soil degradation has been underestimated. Sensitivity to soil degradation is implicit in the assessment of the sustainability of land management practices, with wide recognition of the fact that...
Syers, J. K.
Long term prognosis of reactive salmonella arthritis
Digital Repository Infrastructure Vision for European Research (DRIVER)
OBJECTIVES�Reactive joint complications triggered by salmonella gastroenteritis are increasingly reported, but the outcome and long term prognosis of the patients is incompletely known. This study looked at the prognosis of salmonella arthritis in patients hospitalised in 1970-1986.?METHODS�Hospital records from two hospitals in southern Finland were screened for patients with the discharge diagnosis of salmonellosis or reactive, postinfectious arthritis or Reiter's disease. For the...
Leirisalo-repo, M.; Helenius, P.; Hannu, T.; Lehtinen, A.; Kreula, J.; Taavitsainen, M.; Koskimies, S.
Establishment of a cohort for the long-term clinical follow-up with dose reconstruction under the joint medical research project conducted by Sasakawa Memorial Health Foundation (Japan) and the Research Institute of Radiation Hygiene (Russia)
International Nuclear Information System (INIS)
The cohort of children in the western districts of the Bryansk Region of Russia exposed to radiation following the Chernobyl accident is described in this paper. The cohort was selected under the Joint Medical Research Project on Dosimetry Associated with the Chernobyl Accident conducted by Sasakawa Memorial Health Foundation (SMHF, Japan) and the Research Institute of Radiation Hygiene (RIRH, Russia). The subjects of the Research Project are those people residing in the most contaminated areas of Russia who was 0 to 10 years old at the time of exposure. At the moment the cohort comprises 1210 subjects, though this number may slightly decrease in course of a follow-up in view of migration of population. Most of cohort subjects were examined on their health status within the framework of the Chernobyl Sasakawa Health and Medical Cooperation Project (CSHMCP) from 1991-1996. In view of the main findings of studies in CSHMCP were thyroid abnormalities, selection of subjects was conducted on the basis of the credible estimates of thyroid dose. Preference for subjects to be included into the cohort was defined by the availability of health examination data from previous study (1991-1996) and individual dosimetry, environmental and social data that may prove useful for reconstruction of individual dose. The primary data analyzed for subjects selection are measurements of iodine-131 in the thyroid in May-June 1986, questionnaire data on individual food habits and early measurements of radiocesium in the body of subjects made by RIRH from May to September 1986. Plausible analytical models were applied to calculate thyroid dose from available data. Previously worked out methods of thyroid dose reconstruction using early measurement data of radiocesium content in the body and questionnaire data on individual consumption of locally produced milk were reevaluated. Basing on these analytical procedures, the individual thyroid dose was ascribed to each member of the cohort. The preliminary distribution of internal radiation doses to the thyroid among subjects of the cohort is presented in the paper. The summary characteristics of dose distribution for cohort subjects seems to be reasonably credible, whereas, the individual doses to particular subjects are evaluated with essential degree of uncertainty. The further stage of dose reconstruction for a cohort study, that is now in progress, consists of reduction of these uncertainties by using additional (newly derived) questionnaire information, as well as by taking into account contribution of external radiation to thyroid dose and updating analytical procedures to interpret primary data. Finally, the distribution of subjects into several thyroid dose ranges, from 2 Gy, would be an acceptable approximation for the purposes of radiation epidemiology in a trial to access the radiation risk of developing thyroid diseases. (author)
Compensatory network changes in the dentate gyrus restore long-term potentiation following ablation of neurogenesis in young-adult mice
Digital Repository Infrastructure Vision for European Research (DRIVER)
It is now well established that neurogenesis in the rodent subgranular zone of the hippocampal dentate gyrus continues throughout adulthood. Neuroblasts born in the dentate subgranular zone migrate into the granule cell layer, where they differentiate into neurons known as dentate granule cells. Suppression of neurogenesis by irradiation or genetic ablation has been shown to disrupt synaptic plasticity in the dentate gyrus and impair some forms of hippocampus-dependent learning and memory. Us...
Singer, Benjamin H.; Gamelli, Amy E.; Fuller, Cynthia L.; Temme, Stephanie J.; Parent, Jack M.; Murphy, Geoffrey G.
Long-term sensitization training in Aplysia leads to an increase in the expression of BiP, the major protein chaperon of the ER
Digital Repository Infrastructure Vision for European Research (DRIVER)
Long-term memory for sensitization of the gill- and siphon-withdrawal reflexes in Aplysia californica requires RNA and protein synthesis. These long-term behavioral changes are accompanied by long-term facilitation of the synaptic connections between the gill and siphon sensory and motor neurons, which are similarly dependent on transcription and translation. In addition to showing an increase in over-all protein synthesis, long-term facilitation is associated with changes in the expression o...
Long-term governance for sustainability
International Nuclear Information System (INIS)
Meritxell Martell spoke of the long-term aspects of radioactive waste management. She pointed out that decision-making processes need to be framed within the context of sustainability, which means that a balance should be sought between scientific considerations, economic aspects and structural conditions. Focusing on structural aspects, Working Group 3 of COWAM-Spain came to the conclusion that the activity of the regulator is a key factor of long-term management. Another finding is that from a sustainability perspective multi-level governance is more effective for coping with the challenges of radioactive waste management than one tier of government-making decisions. The working group also felt that the current Local Information Committees need to evolve towards more institutionalized and legitimized mechanisms for long-term involvement. Ms. Martell introduced a study comparing the efficiency of economic instruments to advance sustainable development in nuclear communities vs. municipalities in mining areas. The study found that funds transferred to nuclear zones had become a means to facilitate local acceptance of nuclear facilities rather than a means to promote socio-economic development. Another finding is that economic instruments are not sufficient guarantees of sustainable development by themselves; additional preconditions include leadership, vision and entrepreneur-ship on the part of community leaders, private or public investments, among others. Finally, Ms. Martell summarised the challenges faced by the Spanish radioactive waste management programme, which include the need for strategic thinking, designing the future in a participatory fashion, and working with local and regional governments and citizens to devise mechanisms for social learning, economic development and environmental protection. (author)
Long-term plant availability of actinides
International Nuclear Information System (INIS)
Environmental releases of actinide elements raise issues about which data are very limited. Quantitative information is required to assess the long-term behavior of actinides and their potential hazards resulting from the transport through food chains leading to man. Of special interest is the effect of time on the changes in the availability of actinide elements for uptake by plants from soil. This study provides valuable information on the effects of weathering and aging on the uptake of actinides from soil by range and crop plants grown under realistic field conditions
Natural analogs. Long-term system analysis
International Nuclear Information System (INIS)
The natural analogs are systems evolving with freedom within the nature during very large periods of time (geological periods) and because of their lithological, structural, geochemical and hydrogeological context present a big similitude with the total or partial performance of some systems suggested as geological deep storage sites for high level radioactive wastes. The knowledge and study of such systems shed light into the performance of waste deposits at long-term scenarios. The different studies about analogs in Canada (Cigar lake) Gabon (Oko), Spain (Berrocal), Finland (Palmottu) are analyzed
Human Behaviour in Long-Term Missions
In this session, Session WP1, the discussion focuses on the following topics: Psychological Support for International Space Station Mission; Psycho-social Training for Man in Space; Study of the Physiological Adaptation of the Crew During A 135-Day Space Simulation; Interpersonal Relationships in Space Simulation, The Long-Term Bed Rest in Head-Down Tilt Position; Psychological Adaptation in Groups of Varying Sizes and Environments; Deviance Among Expeditioners, Defining the Off-Nominal Act in Space and Polar Field Analogs; Getting Effective Sleep in the Space-Station Environment; Human Sleep and Circadian Rhythms are Altered During Spaceflight; and Methodological Approach to Study of Cosmonauts Errors and Its Instrumental Support.
Osteoarthropathy in long-term hemodialysis patients
International Nuclear Information System (INIS)
The authors reviewed hand and wrist films of 81 patients who had undergone hemodialysis for a minimum of 5 and a mean duration 7.5 years. The films of 32 patients showed arthritic changes consisting of articular erosions, joint space narrowings, periarticular cysts, and osteopenia. Five of these patients had subcutaneous or periarticular calcific deposits. The frequency and severity of the radiographic findings increased with increasing duration of dialysis. It appears that in addition to the well-recognized secondary hyperparathyroidism there is a second commonly occurring osteoarthropathy (40% in this series) related to long-term hemodialysis
Long-term environmental behaviour of radionuclides
Energy Technology Data Exchange (ETDEWEB)
The radioactive pollution of the environment results from the atmospheric nuclear weapons testing (during the mid-years of twentieth century), from the development of the civilian nuclear industry and from accidents such as Chernobyl. Assessing the resulting radiation that humans might receive requires a good understanding of the long-term behaviour of radionuclides in the environment. This document reports on a joint European effort to advance this understanding, 3 multinational projects have been coordinated: PEACE, EPORA and LANDSCAPE. This report proposes an overview of the results obtained and they are presented in 6 different themes: (i) redistribution in the soil-plant system, (ii) modelling, (iii) countermeasures, (iv) runoff (v) spatial variations, and (vi) dose assessment. The long term behaviour of the radionuclides {sup 137}Cs, {sup 90}Sr and {sup 239-240}Pu is studied through various approaches, these approaches range from in-situ experiments designed to exploit past contamination events to laboratory simulations. A broad scope of different ecosystems ranging from arctic and boreal regions down to mediterranean ones has been considered. (A.C.)
Brechignac, F.; Moberg, L.; Suomela, M
Long term testing of PSI-membranes
Energy Technology Data Exchange (ETDEWEB)
Long term tests of PSI membranes based on radiation-grafted FEP and ETFE films were carried out and FEP-based membranes were evaluated by monitoring the in-situ membrane area resistance measured by a current pulse method. By modifying our irradiation procedure and using the double crosslinking concept we obtain reproducible membrane cell lifetimes (in term of in-situ membrane resistance) of greater than 5000 hours at 60-65{sup o}C. Preliminary tests at 80-85{sup o}C with lifetimes of greater than 2500 demonstrate the potential long term stability of PSI proton exchange membranes based on FEP over the whole operating temperature range of low-temperature polymer electrolyte fuel cells. Radiation grafted PSI membranes based on ETFE have better mechanical properties than those of the FEP membranes. Mechanical properties are particularly important in large area cells and fuel cell stacks. ETFE membranes have been tested successfully for approximately 1000 h in a 2-cell stack (100 cm{sup 2} active area each cell). (author) 4 figs., 4 refs.
Huslage, J.; Brack, H.P.; Geiger, F.; Buechi, F.N.; Tsukada, A.; Scherer, G.G. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)
Institutionalization and Organizational Long-term Success
Directory of Open Access Journals (Sweden)
Full Text Available Institutionalization processes have an ambivalent effect on organizational long-term success. Even though they foster organizational stability and permanence, they also bring about rigidity and resistance to change. As a result, successful organizations are likely to lose their competitive advantage over time. The paper addresses this issue through the investigation of the institutionalization processes of two long-lived companies: General Electric, a firm that has been a long-term success and its rival, Westinghouse, which was broken up after eleven decades of existence. The longitudinal, multilevel analysis of firms and industry has identified two different modes of organizational institutionalization. The reactive mode gives rise to rigidity and change resistance, much like institutional theory predicts; the proactive mode, on the other hand, neutralizes those negative effects of institutionalization processes. In the reactive mode, structure predominates. In the proactive mode, agency plays a major role in organizational institutionalization, and in managing the organization�s relations with the environment, clearly contributing to environmental institutionalization.
Denise L. Fleck
Institutionalization and organizational long-term success
Scientific Electronic Library Online (English)
Full Text Available SciELO Brazil | Language: English Abstract in english Institutionalization processes have an ambivalent effect on organizational long-term success. Even though they foster organizational stability and permanence, they also bring about rigidity and resistance to change. As a result, successful organizations are likely to lose their competitive advantage [...] over time. The paper addresses this issue through the investigation of the institutionalization processes of two long-lived companies: General Electric, a firm that has been a long-term success and its rival, Westinghouse, which was broken up after eleven decades of existence. The longitudinal, multilevel analysis of firms and industry has identified two different modes of organizational institutionalization. The reactive mode gives rise to rigidity and change resistance, much like institutional theory predicts; the proactive mode, on the other hand, neutralizes those negative effects of institutionalization processes. In the reactive mode, structure predominates. In the proactive mode, agency plays a major role in organizational institutionalization, and in managing the organization's relations with the environment, clearly contributing to environmental institutionalization.
Denise, Fleck.
Long-term preservation of anammox bacteria.
Deposit of useful microorganisms in culture collections requires long-term preservation and successful reactivation techniques. The goal of this study was to develop a simple preservation protocol for the long-term storage and reactivation of the anammox biomass. To achieve this, anammox biomass was frozen or lyophilized at two different freezing temperatures (-60�C and in liquid nitrogen (-200�C)) in skim milk media (with and without glycerol), and the reactivation of anammox activity was monitored after a 4-month storage period. Of the different preservation treatments tested, only anammox biomass preserved via freezing in liquid nitrogen followed by lyophilization in skim milk media without glycerol achieved stoichiometric ratios for the anammox reaction similar to the biomass in both the parent bioreactor and in the freshly harvested control treatment. A freezing temperature of -60�C alone, or in conjunction with lyophilization, resulted in the partial recovery of the anammox bacteria, with an equal mixture of anammox and nitrifying bacteria in the reactivated biomass. To our knowledge, this is the first report of the successful reactivation of anammox biomass preserved via sub-zero freezing and/or lyophilization. The simple preservation protocol developed from this study could be beneficial to accelerate the integration of anammox-based processes into current treatment systems through a highly efficient starting anammox biomass. PMID:21590289
Rothrock, Michael J; Vanotti, Matias B; Sz�gi, Ariel A; Gonzalez, Maria Cruz Garcia; Fujii, Takao
Behavioral effects of long-term exposure to organic solvents
Energy Technology Data Exchange (ETDEWEB)
Epidemiological studies have detected an increased risk of neuropsychiatric diseases among groups occupationally exposed to organic solvents. Psychological studies of solvent exposed workers have investigated both cognitive and sensory and motors functions. Most of these studies have dealt with trichloroethylene, toluene, styrene, and mixtures of organic solvents. Most of these studies have found a decline in the sensory and motor functions. Of the cognitive functions especially short-term memory has proved to be sensitive to solvent exposure. Also some implications of declined visuoconstructive abilities have been found. It has been possible to analyze exposure-response and exposure-effect relationships between exposure and psychological findings only for some single studies, because reliable measures for long-term solvent exposure have usually not been available. The measurement of personality characteristics among solvent exposure workers has been another neglected area.
Lindstroem, K.
Long-term memory of individual identity in ant queens
Digital Repository Infrastructure Vision for European Research (DRIVER)
Remembering individual identities is part of our own everyday social life. Surprisingly, this ability has recently been shown in two social insects. While paper wasps recognize each other individually through their facial markings, the ant, Pachycondyla villosa, uses chemical cues. In both species, individual recognition is adaptive since it facilitates the maintenance of stable dominance hierarchies among individuals, and thus reduces the cost of conflict within these small societies. Here, ...
Dreier, Stephanie; Zweden, Jelle S.; D Ettorre, Patrizia
Memorabeatlia: a naturalistic study of long-term memory.
Seventy-six undergraduates were given the titles and first lines of Beatles' songs and asked to recall the songs. Seven hundred and four different undergraduates were cued with one line from each of 25 Beatles' songs and asked to recall the title. The probability of recalling a line was best predicted by the number of times a line was repeated in the song and how early the line first appeared in the song. The probability of cuing to the title was best predicted by whether the line shared words with the title. Although the subjects recalled only 21% of the lines, there were very few errors in recall, and the errors rarely violated the rhythmic, poetic, or thematic constraints of the songs. Acting together, these constraints can account for the near verbatim recall observed. Fourteen subjects, who transcribed one song, made fewer and different errors than the subjects who had recalled the song, indicating that the errors in recall were not primarily the result of errors in encoding. PMID:2319962
Hyman, I E; Rubin, D C
Long-term performance of filtration layer
Permeable pavements are commonly employed to capture and divert stormwater before it enters the stormwater or sewer conveyance systems. During a storm event, runoff water passes through the permeable pavement surface, enters a storage gallery and finally exfiltrates into the surrounding soil. Thus, the ability of the system to store an appropriate volume of runoff water is an important consideration for stormwater control design. Traditionally, crushed stone or other porous material has been used to provide the necessary interstitial void space to store the runoff water. Unfortunately, over time the available void space within the storage gallery is reduced due to settlement, biological growth and sediment accumulation. This gradual reduction in void space reduces the long-term effectiveness of these stormwater controls by limiting its ability to store and pass runoff water. This study examined the long-term performance of the storage gallery layer with respect to its ability to both store and pass runoff water. As the porosity within the storage gallery decreased, it was anticipated that volumetric water content within the gallery would increase and that time necessary to drain the gallery would increase as well. The effects of the gallery porosity were assessed over a one-year study using both laboratory experimentation and monitoring data from naturally occurring rain events. Changes in gallery porosity were first assessed by correlating monitoring piezometer data with surface infiltration testing; building a relation between know volume of poured water being used for the test and the associated pressure head at the base of the gallery. As a known volume of water enters the system, volume change in the gallery directly correlate to increases in pressure head. Second, the time required for water to permeate through pavers and gallery layer to trigger the TDRs in the filtration layer and the time to drain it from the crushed stone were calculated and compared by the age of permeable pavement. These data were utilized to develop a model that more appropriately considered changes in gallery porosity. By better understanding the progression of the runoff water through the storage gallery a better assessment of the long-term performance of the entire system can be developed. Future storage gallery designs can be appropriately modified to account for changes within the storage gallery so that volume and flow requirements are maintained throughout the life of the structure.
Radfar, A.; Rockaway, T. D.
Antagonism of lateral amygdala alpha1-adrenergic receptors facilitates fear conditioning and long-term potentiation
Digital Repository Infrastructure Vision for European Research (DRIVER)
Norepinephrine receptors have been studied in emotion, memory, and attention. However, the role of alpha1-adrenergic receptors in fear conditioning, a major model of emotional learning, is poorly understood. We examined the effect of terazosin, an alpha1-adrenergic receptor antagonist, on cued fear conditioning. Systemic or intra-lateral amygdala terazosin delivered before conditioning enhanced short- and long-term memory. Terazosin delivered after conditioning did not affect consolidation. I...
Lazzaro, Stephanie C.; Hou, Mian; Cunha, Catarina; Ledoux, Joseph E.; Cain, Christopher K.
Seasonal variation of long-term potentiation at a central synapse in the medicinal leech
Digital Repository Infrastructure Vision for European Research (DRIVER)
Long-term potentiation (LTP) is a persistent increase in synaptic transmission that is thought to contribute to a variety of adaptive processes including learning and memory. Although learning is known to undergo circannual variations, it is not known whether LTP undergoes similar changes despite the importance of LTP in learning and memory. Here we report that synapses in the CNS of the medicinal leech demonstrate seasonal variation in the capacity to undergo LTP following paired presynaptic...
Grey, Kathryn B.; Burrell, Brian D.
Involvement of Microglia Activation in the Lead Induced Long-Term Potentiation Impairment
Digital Repository Infrastructure Vision for European Research (DRIVER)
Exposure of Lead (Pb), a known neurotoxicant, can impair spatial learning and memory probably via impairing the hippocampal long-term potentiation (LTP) as well as hippocampal neuronal injury. Activation of hippocampal microglia also impairs spatial learning and memory. Thus, we raised the hypothesis that activation of microglia is involved in the Pb exposure induced hippocampal LTP impairment and neuronal injury. To test this hypothesis and clarify its underlying mechanisms, we investigated ...
Analysis of long-term soxhlet tests
International Nuclear Information System (INIS)
Cyclic leaching patterns were exhibited by simulated waste glass and ceramic titanate (w/10% zeolite) materials during long-term elevated temperature soxhlet leaching studies. In the vitreous waste form, these patterns appear to be due to the formation and subsequent spallation of multilayered alteration products which were characterized using electron microprobe analysis. Electron microprobe studies of the leached titanate sample illustrated a more subdued attack of the surface with no alteration layer formation. During fabrication, cesium was concentrated in zeolite pockets which were leached, presumably by a process similar to that for glasses. One difficulty in leaching studies is the large sample volume required when very low concentrations of elements are to be determined. Studies presently in progress indicate that laser excited atomic fluorescence spectrometry is applicable to determining less than picogram quantities of cesium in 50 ?L sample volumes
Energy medicine for long-term disabilities.
Energy medicine techniques derive from traditional Chinese medicine and are based upon the concept that health and healing are dependent upon a balance of vital energy, a still mind, and controlled emotions. Physical dysfunctions result from disordered patterns of energy of long standing and reversal of the physical problem requires a return to balanced and ordered energy. Qi Gong (Chi Kung) is a system which teaches an individual to live in a state of energy balance. Shen Qi is a sophisticated form of Qi Gong which relies on no external physical interventions but rather relies on mind control to prevent illness, heal existing physical and emotional problems, and promote health and happiness. This paper will describe the use of these techniques with people who have long-term physical disabilities. PMID:10381239
Trieschmann, R B
Long-term control of root growth
Energy Technology Data Exchange (ETDEWEB)
A method and system for long-term control of root growth without killing the plants bearing those roots involves incorporating a 2,6-dinitroaniline in a polymer and disposing the polymer in an area in which root control is desired. This results in controlled release of the substituted aniline herbicide over a period of many years. Herbicides of this class have the property of preventing root elongation without translocating into other parts of the plant. The herbicide may be encapsulated in the polymer or mixed with it. The polymer-herbicide mixture may be formed into pellets, sheets, pipe gaskets, pipes for carrying water, or various other forms. The invention may be applied to other protection of buried hazardous wastes, protection of underground pipes, prevention of root intrusion beneath slabs, the dwarfing of trees or shrubs and other applications. The preferred herbicide is 4-difluoromethyl-N,N-dipropyl-2,6-dinitro-aniline, commonly known as trifluralin.
Burton, Frederick G. (West Richland, WA); Cataldo, Dominic A. (Kennewick, WA); Cline, John F. (Prosser, WA); Skiens, W. Eugene (Richland, WA)
Hanford grout: predicting long-term performance
International Nuclear Information System (INIS)
Grouted disposal is being planned for the low-level portion of liquid radioactive wastes at the Hanford site in Washington state. The performance of the disposal system must be such that it will protect people and the environment for thousands of years after disposal. To predict whether a specific grout disposal system will comply with existing and foreseen regulations, a performance assessment (PA) is performed. Long-term PAs are conducted for a range of performance conditions. Performance assessment is an inexact science. Quantifying projected impacts is especially difficult when only scant data exist on the behavior of certain components of the disposal system over thousands of years. To develop defensible results, we are honing the models and obtaining experimental data. The combination of engineered features and PA refinements is being used to ensure that Hanford grout will meet its principal goal: to protect people and the environment in the future
Estimating long-term health effects
International Nuclear Information System (INIS)
The long-term health effects from iodine 131 and cesium 137 as a result of the accident at Chernobyl Nuclear Power Plant in the USSR are discussed. Computer-generated radiation exposure distributions to the population in Europe have resulted in the following estimates: 2000-40,000 thyroid tumor cases from iodine 131 inhalation of which a few percent might be fatal; 10,000-250,000 potential thyroid tumor cases from iodine 131 absorbed via the grass-cow-milk route in the absence of actions by the public health authorities to block this exposure route; 3500-70,000 cancer cases from whole-body doses of cesium 137 (external and internal), of which approximately half might be fatal. Although there are uncertainties in these estimates they serve to indicate the magnitude of the problem
Long term casting with zirconia nozzles
International Nuclear Information System (INIS)
A more reliable and durable tundish metering nozzle has become a necessity at Georgetown Steel because of longer tundish sequences and increasing billet surface quality demands. In 1989 a switch was made from a one piece full nozzle to a composite nozzle consisting of a high percentage zirconia insert combined with a separate lower grade nozzle block. This paper highlights some of the more important related activities of a nozzle improvement program and its impact on plant operation and production goals. It includes a review of the basic characteristics of the zirconia materials, a description of demands on the nozzle by the continuous casting process, and the evolution of the nozzles used at Georgetown Steel. In addition, the important criteria related to successful, long term casting are discussed. a temperature profile based on an unsteady state heat transfer equation is used to model temperature stratification in the nozzle under various conditions. A thermal spalling test procedure is also introduced
Long-term nuclear power optimization study
International Nuclear Information System (INIS)
An energy demand forecasting model, energy systems optimization model and optimal electrical expansion planning model of the Republic of Korea are developed. Using the first model of them, long-term energy and electric power demand to the year 2001 are forcasted, using the second model, the future energy systems especially for the reference year 1981 are analyzed and optimal energy flows are computed through possible energy supply-demand paths. Also, using the third model, the future nuclear power strategies are analyzed by the optimizing total investment costs for different nuclear reaction combination, assuming that there will be three available reactor types, namely, light water reactor, heavy water reactor and fast breeder reactor up to the year 2000 in Korea. (KAERI INIS Section)
[Risk of long-term antisecretory treatment].
At present, pharmacotherapy leading to a reduction in hydrochloric acid production in the stomach constitutes the core treatment strategy for the majority of the upper intestinal tract diseases. Proton pump inhibitors (PPIs) are the predominant therapeutic group. Gastroesophageal reflux disease is the main indication for the long-term PPI use. Chronic use might be associated with adverse reactions. Potential risks take a form of malabsorption of certain food nutrients with their consequent deficiency, bacterial overgrowth and increased incidence of infections as well as altered regulation of proliferation of gastric as well as other mucosas. Individual risks are low; their assessment is mostly based on the results of population studies. Even though the treatment benefits outweigh any potential theoretical risks, it is wise to decide well on the correct indication and to prescribe the lowest effective dose. PMID:20329581
Kroupa, R; Dolina, J
Long-term thalidomide for actinic prurigo.
A 35-year-old man presented at the age of 8 years with recurrent pruritic papulovesicular lesions on his face and body appearing within minutes of light exposure. A recent positive finding of human leukocyte antigen (HLA) DR4 with the rare DRB1*0407 subtype confirmed a diagnosis of actinic prurigo. Thalidomide (100 mg/day) was commenced at the age of 11 years after an unsuccessful trial of other treatments and his lesions resolved within 2 months. Attempts to withdraw thalidomide have resulted in recurrence of photosensitivity and the patient has remained on a virtually continuous maintenance dose of thalidomide (50 mg/ day) for 23 years. His cumulative dose is estimated to be over 400 g. To date, he has not experienced any adverse effects and investigations have shown no evidence of neuropathy. This case illustrates the safe long-term use of thalidomide. PMID:11903163
Yong-Gee, S A; Muir, J B
Long-term reductions in tinnitus severity
Directory of Open Access Journals (Sweden)
Full Text Available Abstract Background This study was undertaken to assess long-term changes in tinnitus severity exhibited by patients who completed a comprehensive tinnitus management program; to identify factors that contributed to changes in tinnitus severity within this population; to contribute to the development and refinement of effective assessment and management procedures for tinnitus. Methods Detailed questionnaires were mailed to 300 consecutive patients prior to their initial appointment at the Oregon Health & Science University Tinnitus Clinic. All patients were then evaluated and treated within a comprehensive tinnitus management program. Follow-up questionnaires were mailed to the same 300 patients 6 to 36 months after their initial tinnitus clinic appointment. Results One hundred ninety patients (133 males, 57 females; mean age 57 years returned follow-up questionnaires 6 to 36 months (mean = 22 months after their initial tinnitus clinic appointment. This group of patients exhibited significant long-term reductions in self-rated tinnitus loudness, Tinnitus Severity Index scores, tinnitus-related anxiety and prevalence of current depression. Patients who improved their sleep patterns or Beck Depression Inventory scores exhibited greater reductions of tinnitus severity scores than patients who continued to experience insomnia and depression at follow-up. Conclusions Individualized tinnitus management programs that were designed for each patient contributed to overall reductions in tinnitus severity exhibited on follow-up questionnaires. Identification and treatment of patients experiencing anxiety, insomnia or depression are vital components of an effective tinnitus management program. Utilization of acoustic therapy also contributed to improvements exhibited by these patients.
Folmer Robert L
Long term results of pneumatic retinopexy
Directory of Open Access Journals (Sweden)
Full Text Available Amin F EllakwaMenoufiya University, Shibin el Kom, Al-Menoufiya, EgyptBackground: Rhegmatogenous retinal detachment is a commonly encountered retinal problem where rapid treatment can prevent irreversible vision loss. Pneumatic retinopexy (PR is a simple, minimally invasive procedure for retinal reattachment.Purpose: This study aimed to assess the long-term anatomical and functional outcome of pneumatic retinopexy in primary rhegmatogenous retinal detachment.Patients and methods: A prospective interventional study was performed. Subjects with rhegmatogenous retinal detachment who underwent pneumatic retinopexy from May 2006 to May 2007 at Menoufiya University Hospital were included in this study with at least 3 years follow-up.Results: A total of 40 cases were included in the study. The mean age of patients was 44.25 � 10.85 years. Reattachment of the retina was achieved in 100% of cases. In 75% of cases, the primary intervention was successful. However, the retina redetached in 20% of these during the first 6 months, requiring reinjection or another procedure. Three years after the first intervention, follow-up measurement of the mean visual acuity of the eyes without reoperation was 0.40 � 0.21 while the mean visual acuity of the eyes which needed additional operations was 0.22 � 0.13.Conclusion: Sixty percent of the cases obtained long-term retinal reattachment with a single operation success (SOS, with good visual recovery and less morbidity than other more invasive procedures like scleral buckling or pars plana vitrectomy, translating to higher productivity for the patient. This procedure, being quicker than the alternatives, also saves the surgeon's time, making PR a good choice for managing primary rhegmatogenous retinal detachment in developing countries.Keywords: pneumatic, retinopexy, rhegmatogenous, retinal detachment
Ellakwa AF
Long term uranium supply for KEPCO
International Nuclear Information System (INIS)
The industrial development of the Republic of Korea lead to strong growth in energy demand. To decrease the dependence on imported oil supplies, the Korea Electric Power Corporation (KEPCO) invested in nuclear power plants, thermal power plants fired with coal and LNG as well as hydroelectric plants. Subsequently, the electrical, generating capacity by coal-fired power plants, has decreased from 72% in 1975 to 24% in 1988. In the same year, the share of the nuclear generating capacity reached 33.4%. The nuclear power programme in the Republic of Korea started in 1978, when the first nuclear power plant, KORI Unit 1, a 587 MW(e)-PWR went into commercial operation. In April 1989, there were a total of eight nuclear power plants with a continued capacity of 6666 MW(e) in operation. One additional plant with 550 MW(e) capacity is nearing completion. Two further NPP are in earlier stages of construction. It is planned that by 1996, these two reactors will be completed and that the total nuclear electricity generating capacity will reach 9616 MW(e) supplying about 47% of the total electricity of the country. Through the end of the century two more NPP with 1000 MW(e) are planned. The uranium requirements for the nuclear programme of the Republic of Korea will increase from over 1200 t U in 1989 to about 2150 t in 2005. As there are no indigenous mineable uranium resources in the country, supplies have to be secured from outside sources, both through short and long term purchase contracts and through investments in uranium projects. At present, about 50% of the requirements through 2000 are covered by long term contracts, while the remainder is planned to be secured from production centres at which KEPCO holds equities as in Dawn Lake, Cigar Lane and Crow Butte, and through spot market purchases. (author). 5 tabs
GEN IV deployment: Long term perspective
International Nuclear Information System (INIS)
At a time when greenhouse gas emissions have to be sharply curbed and when security of energy supplies has to be enhanced, the aim of this study, achieved with the ''CEA built'' GRUS model (Management of the Uranium Resources under STELLA environment), is to assess how nuclear energy can meet an increasing need in electricity over several decades. It deals with the deployment of the various types of reactors, their rate and limits of installation, the constraint of plutonium availability, the impact on uranium consumption as well as options allowing some flexibility to the various constraints. We will analyze, in a worldwide context, and under four scenarios of energy demand (IIASA A2, A3, B and C2) the feasible transitions between the current fleet and a future one. The time scale will go until 2150 according to the lifespan of the reactors in order to cover two fleet replacements. The 16 Mt of conventional uranium resources would be consumed before the end of the century and already engaged around the mid-century if the nuclear fleet were only built up with light water reactors (LWR) and that under all scenarios. Even taking into account unconventional uranium, the resources would be engaged before the end of the century. Therefore the deployment of sole LWRs with current moderation ratios does not seem to be sustainable in the very long term. The fast reactor (FR) deployment would thus be an answer to the resources issues for a long term development of nuclear technology. Nevertheless, the nuclear capacity to be installed with FRs could be limited by plutonium availability. The third generation will thus be operational throughout the century. In addition, we find parameters which should give some flexibility to the deployment of the FRs, such as the launch date or the breeding gain of the FRs, the burn up in LWRs. (author)
A behavioral analysis of the impact of voluntary physical activity on hippocampus-dependent contextual conditioning
Digital Repository Infrastructure Vision for European Research (DRIVER)
Voluntary physical activity induces molecular changes in the hippocampus consistent with improved hippocampal function, but few studies have explored the effects of wheel running on specific hippocampal-dependent learning and memory processes. The current studies investigated the impact of voluntary wheel running on learning and memory for context and extinction using contextual fear conditioning which is known to be dependent on the hippocampus. When conditioning occurred prior to the start ...
Greenwood, Benjamin N.; Strong, Paul V.; Foley, Teresa E.; Fleshner, Monika
Long-term home oxygen therapy.
Oxygen therapy improves mortality and morbidity in hypoxemic patients with COPD. For best results, oxygen should be administered continuously. The general guidelines that qualify a patient for long-term home oxygen therapy are rather explicit, although there are some gray areas, such as increasing exercise performance in normoxemic COPD patients and the treatment of dyspnea in certain patients. The physiologic goals of oxygen therapy are to reverse or prevent tissue hypoxia under the various conditions of life. Patients often experience a fall in oxygen saturation during REM sleep and during exercise. Thus, the oxygen prescription should specify the oxygen setting during wakeful rest, sleep, and exertion. Pulmonary rehabilitation is the definitive long-term management for patients with chronic lung diseases by building endurance, strength, and coping skills. Patients undergoing pulmonary rehabilitation are taught to become active and mobile. The rehabilitation programs have a special role in helping patients to accept and properly administer their own oxygen therapy. Oxygen therapy should be based on mobility and portability. Improvements in the weight and bulk of oxygen containers and the introduction of oxygen-conserving devices have rendered oxygen systems more portable and less costly. The prescription initiates a clinical triad relationship between the patient, physician, and home oxygen vendor. Prescribing home oxygen is now more time-consuming, and the prescription process requires the careful attention of the physician. The prescription must include patient data, the diagnostic reasons for oxygen, the blood gases, the type of system, and the liter-flow for the various living conditions such as rest, sleep, and exertion. Reimbursement for oxygen via Medicare and other carriers will depend upon the physiologic data as well as the successful completion of a rather complex form. Oxygen therapy should be monitored by regular arterial blood gases or pulse oximetry where appropriate. Patients should have a blood gas sample taken upon any change of condition or adjustment of the oxygen flow setting. Successful oxygen therapy should be physician directed, based on a solid understanding of the physiologic processes involved. PMID:2205441
Tiep, B L
Energy Technology Data Exchange (ETDEWEB)
Long-term monitoring (LTM) associated with subsurface contamination sites is a key element of Long Term Stewardship and Legacy Management across the Department of Energy (DOE) complex. However, both within the DOE and elsewhere, LTM is an expensive endeavor, often exceeding the costs of the remediation phase of a clean-up project. The primary contributors to LTM costs are associated with labor. Sample collection, storage, preparation, analysis, and reporting can add a significant financial burden to project expense when extended over many years. Development of unattended, in situ monitoring networks capable of providing quantitative data satisfactory to regulatory concerns has the potential to significantly reduce LTM costs. But survival and dependable operation in a difficult environment is a common obstacle to widespread use across the DOE complex or elsewhere. Deploying almost any sensor in the subsurface for extended periods of time will expose it to chemical and microbial degradation. Over the time-scales required for in situ LTM, even the most advanced sensor systems may be rendered useless. Frequent replacement or servicing (cleaning) of sensors is expensive and labor intensive, offsetting most, if not all, of the cost savings realized with unattended, in situ sensors. To enable facile, remote monitoring of contaminants and other subsurface parameters over prolonged periods, Applied Research Associates, Inc has been working to develop an advanced LTM sensor network consisting of three key elements: (1) an anti-fouling sensor chamber that can accommodate a variety of chemical and physical measurement devices based on electrochemical, optical and other techniques; (2) two rapid, cost effective, and gentle means of emplacing sensor packages either at precise locations directly in the subsurface or in pre-existing monitoring wells; and (3) a web browser-based data acquisition and control system (WebDACS) utilizing field-networked microprocessor-controlled smart sensors housed in anti-fouling sensor chambers. The monitoring network is highly versatile and can be applied to a variety of subsurface sensing scenarios in different media. However, the current project focused on monitoring water quality parameters of pH, oxidation-reduction potential, conductivity, and temperature in groundwater.
Stephen P. Farrington; John W. Haas; Neal Van Wyck
Robotics for Long-Term Monitoring
International Nuclear Information System (INIS)
While long-term monitoring and stewardship means many things to many people, DOE has defined it as The physical controls, institutions, information, and other mechanisms needed to ensure protection of people and the environment at sites where DOE has completed or plans to complete cleanup (e.g., landfill closures, remedial actions, and facility stabilization). Across the United States, there are thousands of contaminated sites with multiple contaminants released from multiple sources where contaminants have transported and commingled. The U.S. government and U.S. industry are responsible for most of the contamination and are landowners of many of these contaminated properties. These sites must be surveyed periodically for various criteria including structural deterioration, water intrusion, integrity of storage containers, atmospheric conditions, and hazardous substance release. The surveys, however, are intrusive, time-consuming, and expensive and expose survey personnel to radioactive contamination. In long-term monitoring, there's a need for an automated system that will gather and report data from sensors without costly human labor. In most cases, a SCADA (Supervisory Control and Data Acquisition) unit is used to collect and report data from a remote location. A SCADA unit consists of an embedded computer with data acquisition capabilities. The unit can be configured with various sensors placed in different areas of the site to be monitored. A system of this type is static, i.e., the sensors, once placed, cannot be moved to other locations within the site. For those applications where the number of sampling locations would require too many sensors, or where exact location of future problems is unknown, a mobile sensing platform is an ideal solution. In many facilities that undergo regular inspections, the number of video cameras and air monitors required to eliminate the need for human inspections is very large and far too costly. HCET's remote harsh-environment surveyor (RHES) is a robotic platform with SCADA capabilities equipped with a sonar-imaging scanner, a high-resolution color CCD camera, and various combinations of sensors. The RHES is controlled remotely via a PC. This paper will discuss the development and application of this system. (authors)
Brief Subthreshold Events Can Act as Hebbian Signals for Long-Term Plasticity
Background Action potentials are thought to be determinant for the induction of long-term synaptic plasticity, the cellular basis of learning and memory. However, neuronal activity does not lead systematically to an action potential but also, in many cases, to synaptic depolarizing subthreshold events. This is particularly exemplified in corticostriatal information processing. Indeed, the striatum integrates information from the whole cerebral cortex and, due to the membrane properties of striatal medium spiny neurons, cortical inputs do not systematically trigger an action potential but a wide range of subthreshold postsynaptic depolarizations. Accordingly, we have addressed the following question: does a brief subthreshold event act as a Hebbian signal and induce long-term synaptic efficacy changes? Methodology/Principal Findings Here, using perforated patch-clamp recordings on rat brain corticostriatal slices, we demonstrate, that brief (30 ms) subthreshold depolarizing events in quasi-coincidence with presynaptic activity can act as Hebbian signals and are sufficient to induce long-term synaptic plasticity at corticostriatal synapses. This �subthreshold-depolarization dependent plasticity� (SDDP) induces strong, significant and bidirectional long-term synaptic efficacy changes at a very high occurrence (81%) for time intervals between pre- and postsynaptic stimulations (?t) of ?110long-term depression (cannabinoid type-1 receptor-activation dependent) as well as long-term potentiation (NMDA receptor-activation dependent). Conclusion/Significance Our data show the existence of a robust, reliable and timing-dependent bidirectional long-term plasticity induced by brief subthreshold events paired with presynaptic activity. The existence of a subthreshold-depolarization dependent plasticity extends considerably, beyond the action potential, the neuron's capabilities to express long-term synaptic efficacy changes.
Fino, Elodie; Deniau, Jean-Michel; Venance, Laurent
Bacterial Cellulose: Long-Term Biocompatibility Studies.
The bacterial cellulose (BC) secreted by Gluconacetobacter xylinus is a network of pure cellulose nanofibres which has high crystallinity, wettability and mechanical strength. These characteristics make BC an excellent material for tissue-engineering constructs, noteworthy for artificial vascular grafts. In this work, the in vivo biocompatibility of BC membranes produced by two G. xylinus strains was analyzed through histological analysis of long-term subcutaneous implants in the mice. The BC implants caused a mild and benign inflammatory reaction that decreased along time and did not elicit a foreign body reaction. A tendency to calcify over time, which may be related to the porosity of the BC implants, was observed, especially among the less porous BC-1 implants. In addition, the potential toxicity of BC nanofibres - obtained by chemical-mechanical treatment of BC membranes - subcutaneously implanted in mice was analysed through bone marrow flow cytometryand histological analyses. At 2 and 4 months post-implantation, the nanofibres implants were found to accumulate intracellularly, in subcutaneous foamy macrophages aggregates. Moreover, no differences were observed between the controls and implanted animals in thymocyte populations and in B lymphocyte precursors and myeloid cells in the bone marrow. PMID:21722421
P�rtile, Renata A N; Moreira, Susana; Costa, Rui M Gil da; Correia, Alexandra; Guard�o, Luisa; Gartner, F�tima; Vilanova, Manuel; Gama, Miguel
Long term results of mandibular distraction
Directory of Open Access Journals (Sweden)
Full Text Available Mandibular distraction osteogenesis has become a popular surgical modality due to its many advantages over conventional orthognathic surgical procedures. However, in spite of the technique having been used for over 15 years, no concrete long term results are available regarding the stability of results. We discuss the various studies which have reported either in favour or against the stablility of results after distraction. We report a series of 6 cases (3 unilateral and 3 bilateral distraction where distraction was carried out before puberty and followed them up to seven years after removal of distractors. This case series shows that results achieved by distraction osteogenesis are unstable or best unpredictable with respect to producing a permanent size increase in the mandible. The role of the distraction osteogenesis in overcoming the pterygomassetric sling is questionable. We suggest a multicenter study with adequate patient numbers treated with a similar protocol and documented after growth cessation to have meaningful conclusions on the debate of distraction osteogenesis versus orthognathic surgery.
Batra Puneet