不同时程的脑缺血对大鼠学习记忆功能及脑皮层乙酰胆碱酯酶活性的影响

目的研究不同时程的脑缺血对大鼠学习记忆能力及脑皮层乙酰胆碱酯酶活性的影响。方法永久性结扎大鼠双侧颈总动脉，分别于术后4h、24h、3d、7d、2周、4周和8周取脑皮层检测乙酰胆碱酯酶（AchE）活性，在2、4、8周时，用通道式水迷宫和避暗试验测试大鼠逃避潜伏期和错误次数。结果术后2周起，模型大鼠潜伏期和错误次数均大于对照组，8周时仍不能恢复。4h起，模型大鼠皮层AchE活性显著升高，持续到2周，8周时趋近恢复。结论经双侧颈总动脉永久结扎后形成的脑缺血状态可引起脑部乙酰胆碱酯酶活性升高和学习记忆功能减退。

Effects of Chronic Cerebral Ischemia on Learning-Memory Ability and Cerebral Acetylcholinesterase Activity

Objective In order to investigate the effects of chronic cerebral ischemia on cerebral acetylcholinesterase(AchE) activity and learning-memory function.Methods Male Sprague-Dawley rats were subjected to permanent bilateral common carotid artery ligation(BCAL).Learning-memory functions examined by water maze and step-through test were performed at 2 week,4 week and 8 week after cerebral ischemia.Cerebral cortical AchE activities were determined at 4 h,24 h,3 d,7 d,2 week,4 week and 8 week after operation of cerebral ischemia.Results In the water maze and step-through tests,each ischemia group showed deficit in learning-memory function since 2 week after BCAL and these deficits did not recover at 8 week after operation.In the cortex area of ischemia group rats,AchE activity was significantly increased from 4 h to 2 week after operation.Conclusion Permanent bilateral ligation of carotid arteries can cause chronic cerebral ischemia status and thus cause increase of acetylcholinesterase activity and learning-memory deficit.