摘要
目的探讨慢性脑缺血大鼠海马区和齿状回突触素表达水平变化与学习记忆之间的关系。方法永久性结扎大鼠双侧颈总动脉,制备慢性前脑缺血大鼠致痴呆实验动物模型,通过水迷宫实验动态观察大鼠空间学习能力;应用免疫组织化学染色法测定慢性脑缺血后大鼠海马区与齿状回突触素表达水平的变化。结果手术后,实验组大鼠的学习记忆能力下降,游迷宫时间延长,进入盲端次数增加,并随缺血时间的延长而逐渐加重,缺血4周后与对照组相比差异有显著性意义(P<0.05)。手术后,实验组大鼠海马区等部位的神经细胞胞浆深染、变性并发生坏死,随着缺血时间的延长,神经细胞逐渐减少,胶质细胞增多。手术后第4周,海马区和齿状回突触素阳性产物表达明显减少(均P<0.05),至第16周或第12周减少最为明显(P<0.05)。结论慢性脑缺血大鼠空间学习记忆力减退可能与海马区和齿状回突触数量减少相关。
Objective To study the relationship between synaptophysin in hippocampus and dentate gyrus with cognitive function in chronic cerebral ischemic rats.Methods The vascular dementia rat model was established by permanent ligation of the common carotid arteries.The water maze test was performed to detect the space learning ability and memory function of rats;and the changing of synaptophysin levels in hip-pocampus and dentate gyrus after chronic cerebral ischemia were detected by immunohistochemical staining.Re sults The cognitive function was impaired postoperation,presented with prolonged swimming time in maze and increased times of entering blind end,the longer the ischemic time,the worse the manifestation,the dif-ference was statistically significant (P<0.05)compared with control(non operated rats).The darkened stain-ing of cytoplasm,degeneration,necrosis of nerve cells were found in hippocampus showed bioplasm,and the number of nerve cells decreased but glial cells increased as the ischemic time prologing.Four weeks after op-eration,there was a progressive decrease of synaptophysin in hippocampus and dentate gryus(P<0.05)and most significant in16weeks(P<0.05).Con clu sion The impairment of cognitive function(space learning memory)in chronic cerebral ischemic rats is related to the decreasing of synapses in hippocampus and dentate gyrus.[
