电针对转基因阿尔茨海默病小鼠海马CA1区超微结构的影响

目的:研究针刺治疗阿尔茨海默病(Alzheimer disease,AD)的超微结构基础。方法:将3月龄的淀粉样前体蛋白(APP)转基因小鼠随机分为模型组和电针组,以相同年龄和背景的C 57 BL/6 J小鼠做正常对照组。电针组取"百会"涌泉"穴,隔日治疗1次,针刺3个月。以LashleyⅢ水迷宫测定小鼠学习记忆能力,以透射电镜观察海马CA 1区的超微结构。结果:电针组小鼠水迷宫游出时间及进入盲端次数明显少于模型组(P<0.05),接近于正常对照组;与正常对照组比较,模型组海马CA 1区超微结构出现线粒体肿胀、嵴断裂或消失,突触变性,毛细血管基膜增厚、轮廓不清;而电针组海马CA 1区超微结构可见突触前终末的突触囊泡明显增多,线粒体嵴形态与微血管结构层次清楚,其特征与正常对照组相近。结论:APP转基因阳性小鼠海马CA 1区超微结构发生类AD变化,学习、记忆行为学能力下降,是AD较理想的动物模型。电针能改善APP转基因小鼠海马CA 1区超微结构,可能是改善AD小鼠学习、记忆能力的形态学基础。

Effect of Electroacupuncture on the Behavior and Hippocampal Ultrastructure in APP 695 V 717 I Transgenic Mice

Objective To investigate the ultrastructural basis underlying electroacupuncture (EA) induced improvement of Alzheimer disease (AD) in transgenic mice. Methods Twelve APP 695 V 717 I transgenic mice were randomly divided into model group and EA group; and other 6 negative transgenic mice (C 57 BL/6 J) were made up of normal control group. After 3 months treatment by EA (15 min per other day, 2 Hz/100 Hz, 3-4 mA) applied to "Baihui" (GV 20) and "Yongquan" (Kl 1), the learning and memory ability of mice was measured by Lashley M water maze test, and the ultrastructural changes of hippocampal CA 1 region was observed by electronic microscopy. Results The swimming escape latency and the number of navigating errors (dead-end forward swimming) in model group were significantly longer and more than those in normal control group (P<0. 05); and those in EA group were considerably shorter and fewer than those in model group (P<0. 05), suggesting an improvement of learning-memory ability after EA. Comparison of the ultrastructure of the neurons in the hippocampal CA 1 region showed swelling of the mitochondria, broken or disappearance of the mitochondrial cristae, degeneration of the synapses, breakage and vague outline of the basement membrane of the blood capillaries in mice of model group; and basically distinct outline of the mitochondrial cristae and microvessels, and more synaptic vesicles in EA group. Conclusion EA may effectively improve the learning-memory capacity of the APP transgenic AD mice and alleviate the pathological changes of neurons of the hippocampal CA 1 region, which may be one of the mechanisms underlying the improvement of AD by EA.