主动跑轮运动促进大鼠脑缺血后认知功能恢复的纹状体脑区多巴胺变化研究

发布时间：2018-02-22 17:10

本文关键词： 脑缺血微透析纹状体多巴胺被动回避反射　出处：《首都体育学院》2017年硕士论文　论文类型：学位论文

【摘要】：研究目的:实验和临床研究已经证明,运动能对脑缺血产生神经保护的作用,但是此过程中的潜在神经化学机制还有待进一步研究。本研究的目的是通过探究主动跑轮运动促进脑缺血后认知功能恢复的纹状体脑区多巴胺的动态变化,由此探讨主动跑轮运动改善脑缺血损伤的机制。研究方法:选取健康3月龄雄性SD大鼠24只,随机将其分为4组:运动4周缺血组(4RI组)、运动1周缺血组(1RI组)、缺血对照组(I组)、假手术组(C组),每组6只。运动4周缺血组、运动1周缺血组大鼠分别进行为期4周和1周的主动跑轮训练,缺血对照组和假手术组不进行主动跑轮训练。在完成4周的主动跑轮训练之后,运动4周缺血组、运动1周缺血组、缺血对照组大鼠进行永久性双侧颈总动脉结扎(2-V0)手术,制备大鼠全脑缺血模型,而假手术组仅暴露双侧颈总动脉,不进行结扎处理。脑缺血前、后运用活体脑内微透析及高效液相色谱电化学联用技术对大鼠纹状体透析液中的多巴胺水平进行测定,微透析实验完成后,将所有大鼠灌流取脑并做组织学鉴定。另外重新选取24只健康3月龄雄性SD大鼠,每组6只,分组及训练方法同上,训练结束后,对运动4周缺血组、运动1周缺血组、缺血对照组大鼠进行永久性双侧颈总动脉结扎,制备全脑缺血模型,在脑缺血后24小时应用被动回避反射评价四组大鼠的学习记忆能力。研究结果:1、与假手组恒定的多巴胺含量相比,I组大鼠2-VO缺血手术后纹状体脑区多巴胺含量显著上升(P0.001),在缺血手术后20分钟上升至最大值,随后逐渐下降。而4RI组和1RI组大鼠2-VO缺血手术前后,大鼠纹状体脑区多巴胺含量变化无显著差异(P0.05)。2、4RI组和1RI组大鼠缺血前纹状体脑区多巴胺基础含量显著高于C组和I组(P0.001)。但是4RI组和1RI组大鼠缺血前纹状体脑区多巴胺基础含量比较无显著差异(P0.05)。3、被动回避反射结果显示,C组大鼠、4RI组大鼠和1RI组大鼠重复训练时间显著长于I组大鼠(P0.001)。C组大鼠、4RI组大鼠和1RI组大鼠重复训练时间相比无显著差异(P0.05)。4、形态学研究结果显示,微透析探针被准确放置在大鼠右侧纹状体,提示脑缺血前后收集的透析液为纹状体脑区神经细胞的外液。研究结论:4周和1周的主动跑轮运动可以显著提高大鼠纹状体脑区多巴胺基础浓度,并且能抑制大鼠脑缺血后纹状体脑区多巴胺的过度释放,降低脑缺血对大鼠学习记忆能力的损害。因此,缺血前的主动跑轮运动抑制脑缺血大鼠纹状体脑区多巴胺水平的快速上升,可能是运动促进脑缺血大鼠认知功能恢复的潜在神经化学机制。
[Abstract]:Objective: experimental and clinical studies have shown that exercise has a neuroprotective effect on cerebral ischemia. However, the underlying neurochemical mechanism of this process remains to be further studied. The aim of this study was to explore the dynamic changes of dopamine in the striatum after cerebral ischemia by exploring the effects of active wheel movement on the recovery of cognitive function in the striatum. Methods: 24 healthy male SD rats aged 3 months were selected to study the mechanism of active wheel running in improving cerebral ischemia injury. The rats were randomly divided into 4 groups: 4 weeks ischemia group, 4 weeks ischemia group, 1 week ischemia group, 1 RI group, ischemia control group, sham operation group C group, 6 rats in each group. The rats in the ischemic group underwent 4 weeks and 1 week of active wheel training, while the ischemic control group and the sham operation group did not. One week of exercise ischemia group, ischemic control group rats underwent permanent bilateral common carotid artery ligation (2-V0) operation, the rat model of global cerebral ischemia was made, while the sham operation group only exposed bilateral common carotid artery without ligation. The dopamine levels in rat striatum dialysate were determined by microdialysis in vivo and electrochemical high performance liquid chromatography (HPLC). In addition, 24 healthy male SD rats aged 3 months were re-selected, 6 rats in each group, divided into groups and training methods. After training, 4 weeks ischemia group and 1 week ischemia group were selected. The model of global cerebral ischemia was established by permanent bilateral common carotid artery ligation in rats of ischemic control group. The learning and memory abilities of the four groups were evaluated by passive avoidance reflex 24 hours after cerebral ischemia. Results: 1: 1, compared with the constant dopamine content in the prosthetic hand group, the dopamine content in the striatum of rats in group I was significantly higher than that in group I after 2-VO ischemia. The peak value of P0.001 increased to a maximum at 20 minutes after ischemic surgery. Then decreased gradually. However, before and after 2-VO ischemia in 4RI group and 1RI group, There was no significant difference in dopamine content in the striatum of rats. The dopamine basal levels in the preischemic striatum of the rats in P0.05 and 1RI groups were significantly higher than those in the C and I groups, but the dopa levels in the preischemic striatum of the 4RI and 1RI groups were significantly higher than those of the rats in the preischemic striatum. The results of passive avoidance reflex showed that the time of repeated training in group C and group 1RI was significantly longer than that in group I (P 0.001), group C (n = 4) and group 1RI (n = 1). There was no significant difference between the two groups (P0.05. 4). The morphological results showed that, The microdialysis probe was placed exactly in the right striatum of the rat. The results suggest that the dialysate collected before and after cerebral ischemia is the extracorporeal fluid of the neurons in the striatum. Conclusion the active wheel movement at 4 weeks and 1 week can significantly increase the basic concentration of dopamine in the striatum of rats. And it can inhibit the excessive release of dopamine in striatum after cerebral ischemia, and decrease the impairment of learning and memory ability after cerebral ischemia in rats. The active wheel running before ischemia inhibits the rapid increase of dopamine level in the striatum of rats with cerebral ischemia, which may be a potential neurochemical mechanism by which exercise can promote the recovery of cognitive function in rats with cerebral ischemia.
【学位授予单位】：首都体育学院
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：G804.2

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