血管性痴呆大鼠记忆障碍与海马胆碱能神经元关系的研究

A study of the relationship between hypomnesia and cholinergic neurons of hippocampus in vascular dementic rats

目的探讨血管性痴呆（ＶＤ）记忆障碍的发病机理。方法采用改良的Ｐｕｌｓｉｎｅｌｉ４－血管阻断全脑缺血法，建立ＳＤ大鼠血管性痴呆模型，进行Ｙ－型迷宫和胆碱乙酰转移酶（ＣｈＡＴ）免疫组化测定。结果实验组在手术２周后出现严重的空间分辨学习记忆能力障碍，海马ＣＡ１区ＣｈＡＴ免疫反应阳性神经元分布及其数量较对照组显著减少，且与学习记忆障碍呈正相关。结论反复全脑缺血所致ＶＤ的学习记忆功能障碍，其原因可能为中枢胆碱能神经元受损致脑内学习记忆的神经生化基础海马环路损害。

Objective To study the mechanism of hypomnesia in vascular dementia(VD). Methods A repeated transient global ischemia was performed in SD rats by a modified Pulsinelli's 4vessel occlusion(4VO) method. Thus the animal VD models were established.The rats were tested by Ytype maze and the brain tissues were studied by immunohistochemical method for cholinergic acetyltransferase (ChAT) as a marker. Results The experimental group showed severe impairment of spatial memory 2 weeks after ischemic operation, with a more marked decrease of positive ChAT like immunoreaction in CA1 sector of hippocampus than control group, which had a significant positive correlation with memory. Conclusions The mechanism of the hypomnesia of VD caused by repeated global ischemia might be due to the impairment of CNS cholinergic neurons resulting mainly the destruction of the biochemical basis of hippocampus circuit.