of maintenance, lower breeding numbers, and the limited neurogenerative abilities. To some extent, adult neurogenesis in rodents may be induced by selective disruption of Notch signalling in astrocytes: this produces novel neurons which functionally integrate into the striatal circuit. Adult neurogenesis in the subventricular zone and dentate gyrus of rodents generates oxidative stress and production of reactive oxygen species that can damage both DNA and lipids. The oxidative stress caused by postnatal neurogenesis may significantly contribute to the reduced learning and memory that occurs with increasing age. Octopus A cephalopod also known as the common octopus, this organism has an intricate nervous system that demonstrates the brains capacity to produce new cells. In this case and in other taxa when compared, these organisms adapt to unpredictable environments by using newly formed brain cells. This is over a short life-span (female about one year) where wild common octopuses focus most of their energy on mating and offspring care. Findings suggest that the octopus vulgaris like other short-lived species have a complex hippocampal proliferation, needed for spacial/navigation, and short and long-term memory. Chickadees Black-capped chickadees are a well-known model species in the field of neuroscience for their neural mechanisms in song vocalization, plasticity, and memory. Black-capped chickadees are different from other species in the larger group of songbirds because they are characterized by food-caching behaviors. Due to this behavior, chickadees can be described through their remarkable spatial memory. Seasonal changes in hippocampal densities have been described since 1994 where neuronal survival peaks during the fall (October), measured by thymidine (see tracking neurogenesis below) labeled cells, weeks after injection. When compared to non-food caching birds such as the house sparrow, chickadees had significantly more hippocampal neuron recruitment from fall to spring. The changes in hippocampal density is directly associated with increased hoarding behavior, especially during the winter when better spatial memory maximizes their survival. Over the 2 decades since the initial discovery, the specific role of chickadee hippocampus in memory has gained wide attention. In an experimental setting, hippocampal lesions affect memory for locations, validating previous notions for this specific role. Further, experimentally inhibiting neuronal proliferation decreases scores on spatial memory tasks, supporting that new neurons hold the same role as pre-existing ones. The specific function of the hippocampus, coupled with seasonal changes in their volume, point towards their temporary advantages for spatial memory consolidation. Taken all together, adult neurogenesis in the hippocampus