PMC10282974_01
Study design and locations of the recording electrodes. (A) TBI was induced in 28 rats, among which 15 completed the 30-day vEEG study. After TBI induction (craniectomy location is shown as a green circle in panel B), four epidural screw electrodes (placements in panel [B]: C1, ipsilateral frontal; O1, ipsilateral occipital; C2, contralateral frontal; O2, contralateral occipital) were implanted, and rats were immediately placed under continuous vEEG monitoring for 1 month. Rats were tested in the beam walking test at baseline and on D30 post-TBI. Body weight was recorded on surgery day and then on D2, D9, and D30. Finally, on D31-D34 post-TBI, rats were transcardially perfused for histology, and brains were sectioned and stained with thionin to evaluate the lesion location and area as well as cerebral and cortical volumes. AP, anteroposterior; D, day; EEG, electroencephalography; G, ground; L, lateral; mm, millimeter; Ref, reference; TBI, traumatic brain injury; vEEG, video electroencephalography; Wk, week.
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PMC10282974_01_neur.2022.0090_figure1.jpg
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Ferris and colleagues, who reported a 1.8-fold increase in brain volume of a 2-year-old R222 RNaseT2 knockout rat with severe "spontaneous hydrocephalus." The etiology of the "pre-existing" hydrocephalus (e.g., genetic) in rat #112 is unknown; another question is how a brain twice the volume of the normal brain could fit into the regular-sized skull. Ferris and colleagues did not report any abnormalities in skull size or shape either, even though the skull appears larger than normal in magnetic resonance imaging (MRI) shown in their Figure 1.
PMC10282974_02