Proliferation and differentiation of endogenous neural stem cells in subventricular zone in rats after traumatic craniocerebral injury / 南方医科大学学报

<p><b>OBJECTIVE</b>To observe the time course of proliferation and differentiation of neural stem cells (NSCs) in the subventricular zone (SVZ) of rats following traumatic craniocerebral injury (TBI).</p><p><b>METHODS</b>Forty-eight SD rats were randomized into 3 groups, namely the control group without any treatment, the sham-operated group with scalp incision and preparation of a cranial window, and TBI group with craniocerebral injury induced by Feeney's method. With nestin and BrdU as two cell markers, NSE as the neuron-specific marker and GFAP as the glial cell marker, immunofluorescence assay with double labeled antibodies was performed to examine the proliferation and differentiation of endogenous NSCs in the SVZ at different time points after TBI.</p><p><b>RESULTS</b>s The numbers of cells positive for nestin/NSE, nestin/GFAP, BrdU/NSE, and BrdU/GFAP in the SVZ of the rats increased significantly after TBI. The positive cells began to increase at 1 day after TBI, reached the peak level at day 3 and became normal at day 14, showing significant differences between the time points of measurement following TBI and from the cell numbers in the control group measured at the same time points. The cells positive for nestin/ GFAP showed the most distinct increase in the SVZ of the rats with TBI.</p><p><b>CONCLUSION</b>TBI results in mobilization of the NSCs in the SVZ on the injured side to cause the proliferation and differentiation of the endogenous NSCs. The SVZ is one of the most important germinal centers of NSC proliferation and differentiation.</p>

Time course of calpain activity changes in rat neurons following fluid percussion injury and the interventional effect of mild hypothermia / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the time course of calpain activity changes in rat neurons following fluid percussion injury (FPI) under normothermia (37 degrees celsius;) and mild hypothermia (32-/+0.5) degrees celsius;.</p><p><b>METHODS</b>In vitro cultured rat neurons were subjected to FPI followed by application of mild hypothermia for intervention at different time points, and the changes in intraneuronal calpain activity following FPI and the interventional effect of mild hypothermia on calpain activity were evaluated by UV-spectrophotometry at different time points.</p><p><b>RESULTS</b>Remarkable changes occurred in calpain activity in the neurons following FPI at 37 degrees celsius;, and mild hypothermia produced obvious interventional effect on calpain activity in close relation to the timing of intervention initiation.</p><p><b>CONCLUSION</b>Intraneuronal calpain activity changes following FPI are involved in the pathological process of cellular injury, and mild hypothermia might offer protection against traumatic brain injury to some extent by regulating calpain activity. The interventional effect of mild hypothermia is associated with the timing of the intervention initiation.</p>