缺血后处理对全脑缺血损伤后神经元结构可塑性及记忆的影响

Effects of ischemic postconditioning on neuron structure plasticity and memory after global cere- bral ischemia injury in rats

目的 观察缺血后处理（Ischemic postconditioning）对全脑缺血损伤后神经元结构可塑性及记忆的影响,从形态学的角度对缺血后处理的保护作用机制进行探讨.方法 SD成年雄性大鼠36只,随机数字表法分为为假手术组、全脑缺血15 min组、全脑缺血＋后处理组,每组12只,处理方式为缺血/再灌注各15 s,循环3次.每组6只以Morris水迷宫观察学习记忆,重复性方差分析处理数据,另外6只以高尔基（golgi）银染观察神经元形态与树突棘密度变化,使用方差分析进行统计分析.结果 缺血后处理组逃避潜伏期较全脑缺血组明显缩短（第3天P=0.014,第4天P=0.040第5天P=0.001）,缺血后处理组树突棘密度较全脑缺血组明显增多（F=562.820,P＜0.01） 结论缺血后处理对脑缺血所致的记忆损伤有明显的保护作用,其机制可能与减少树突棘的损伤有关.

Objective To observe the effect of ischemic postconditioning on neuron structure plasticity and memory after global cerebral ischemia injury in rats and discuss the protection mechanism from aspect of Morphology. Methods A total of 36 SD male rats were randomly divided into sham operation group, global cerebral ischemia for 15 min group and global cerebral ischemia plus postconditioning group, 12 rats per group. The pullsinelli 4 vessel occlusion was applied to produce the models of global cerebral ischemia reperfusion injury, common carotid arteries （CCA） occlusion with 15 min and postconditioning with three cycles, of 15 sec release and 15 sec occlusion （15s/15s）. Six rats from each group were evaluated by Morris Maze test for the ability of space learning and memory and the other six rats were evaluated by golgi stain for morphologic change of neuron. Results The ischemic postcondtioning group showed significant shorter mean escape latency compared with the sham operated group （ at day 3, P =0. 014; at day 4, P =0.040; at day 5, P =0.001 ）. The density of dendritic spine in ischemic postcondtioning group was increased more significantly compared with ischemic group （ F = 562. 820,P 〈 0. 01 ）. Conclusion Ischemic postconditioning has obvious protective effect on cerebral ischemiainduced memory impairment, which may be related to alleviation of dendritic spine injury.