丰富环境对慢性脑低灌注大鼠认知功能的恢复及脑血流代偿的影响

Effects of Enriched Environment on Cognition Recovery and Cerebral Blood Flow Compensation in Chronic Cerebral Hypoperfusion Rats

目的:观察脑微血管新生在丰富环境改善认知功能中的作用。方法:随机将大鼠分为假手术(sham)组、双侧颈总动脉结扎手术+标准环境(2VO+SE)组和2VO手术+丰富环境(2VO+EE)组。采用物体识别试验、Morris水迷宫、Western-blot及免疫组织化学法分别检测大鼠的认知、VEGF蛋白表达水平及微血管密度(MVD)。结果:2VO+SE组大鼠识别新物体能力下降,丰富环境可以缓解这种下降。2VO+SE组大鼠Morris水迷宫中逃避潜伏期延长,丰富环境自第3天起可以缩短大鼠的逃避潜伏期。2VO术后大鼠海马及皮层VEGF蛋白表达水平增加,2VO+EE组增加更显著。MVD测定提示2VO术后大鼠海马及皮层MVD增加,2VO+EE组增加更显著。结论:丰富环境可能增加慢性脑低灌注大鼠海马及皮层区微血管的代偿性增生,提高其血流恢复的代偿能力,进而改善认知功能。

Objective： To explore whether the enriched environment can improve cognition by neovascu- larization in rats. Methods： All the rats were randomly divided into sham-operated （sham） group, bilateral carotid artery ligation （2VO） ＋ standard environment （SE） group and 2VO ＋ enriched environment （2VO＋EE） group. Object recognition test, Morris water maze, Western-blot and immunohis- tochemistry were used to detect the cognition, the level of VEGF protein expression, and microvessel density（MVD）. Results： The ability of 2VO＋SE rats to identify new objects was reduced, while enriched environment could mitigate this decline. The escape latencies of 2VO＋SE rats were extended, while enriched environment could shorten the escape latencies since the third day. 2VO could increase VEGF protein levels and MVD in hippocampus and cortex, and the effect was more obvious under enriched environment. Conclusion： Enriched environment could increase the microvascular compensatory hyperplasia after chronic cerebral hypoperfusion and improve the cognition.