大鼠轻型颅脑损伤后星形胶质细胞与神经元的病理改变

目的 探讨轻型颅脑损伤（TBI）后神经元及星形胶质细胞改变的病理生理过程。方法 将24只成年SD大鼠随机分为轻型TBI组（n=18）和假手术组（n=6），轻型TBI组又分为伤后3 h（n=6）、伤后24 h（n=6）、伤后72 h（n=6）三亚组。采用液压冲击法制作轻型TBI模型。采用胶质纤维酸性蛋白（GFAP）染色检测星形胶质细胞，采用Fluoro-Jade B（FJ-B）荧光染色检测变性神经元。结果 与假手术组相比，轻型TBI后3 h、24 h、72 h邻近顶叶皮质、海马CA2/3区GFAP阳性细胞数量均明显减少（P<0.05）；缺失区周围星形胶质细胞肿胀增生明显。FJ-B阳性神经元在损伤后3 h无明显增加（P>0.05），伤后24 h皮层区FJ-B阳性神经元显著增加（P<0.05），伤后72 h海马区FJ-B阳性神经元显著增加（P<0.05）。伤后72 h伤侧皮层区与海马区GFAP阳性细胞数和FJ-B阳性细胞数呈显著负相关（r=-0.8285，P<0.05）。结论 轻型TBI后星形胶质细胞超急性期（3 h）即出现损害和胶质反应，神经元则在急性期（24 h）至亚急性期（72 h）出现明显损害，星形胶质细胞缺失程度可以反应神经元损伤程度。

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

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.