Pathological changes in astrocytes and neurons after mild traumatic brain injury in rats

LIN Jing; ZHANG Wei; ZHENG Xiao-qiang; CHENG Hong-wei; GAO Rui-ting; SONG Chao-li

doi:10.13798/j.issn.1009-153X.2018.04.008

Abstract：Objective To study the pathological changes in astrocytes and neurons in the rats with mild traumatic brain injury (TBI).Methods Twenty four adult SD rats were randomly divided into 4 groups of 6 animals each,i.e.sham operation group and 3,24 and 72 hours after injury groups. Parasagittal fluid percussion was performed to produce mild TBI in all the groups except the sham operation group. Brain sections were stained with both glial fibrillary acidic protein (GFAP) immunohistochemistry and Fluoro-Jade (FJ-B) histofluorescence in order to observe pathological changes in astrocytes and neurons, respectively. Results The number of astrocytes was significantly reduced in the parietal cortex and hippocampus CA2 and CA3 3,24 and 72 hours after mild TBI and around them there were hyperplasia of glial cells compared with the sham operation group (P<0.05). FJ-B positive neurons, i.e. degenerative neurons were significantly increased in cortex and hippocampus 24 and 72 hours after the mild TBI compared with the sham operation group(P<0.05).The number of GFAP positive astrocyts was significantly negatively correlated with the number of FJ-B positive neurons in the parietal cortex and hippocampus CA2 and CA3 72 hours after injury(r=-0.8285;P<0.05).Conclusions There are astrocyte loss and astrogliosis at the ultra-acute stage(3 hours)after the mild TBI and neuronal degeneration is significant at later stage(24 hours or later)after mild TBI.Loss of astrocytes can reflect neuronal injury.