有氧训练干预对大鼠小脑神经细胞黏附分子表达和学习记忆的影响

Effects of Aerobic Exercise Intervention on the Expression of Neural Cell Adhesion Molecule in Cerebellum and Learning and Memory of Rats

目的:观察不同负荷游泳运动对大鼠学习和记忆能力的影响,同时观察小脑神经细胞黏附分子(NCAM)表达的变化,试图探讨运动干预对大鼠小脑学习记忆能力影响的可能机制。方法:将2月龄雄性SD大鼠随机分为正常组(control,n=10,正常喂养8周)、中等负荷运动组(MT,n=10,中等负荷游泳8周)和高度负荷运动组(HT,n=10,高度负荷游泳8周)。采用Morris水迷宫测定大鼠的空间学习和空间记忆能力,ELISA实验检测三组大鼠的血睾酮含量,real time RT–PCR和Western Blot实验分别检测小脑NCAM mRNA和蛋白的表达。结果:Morris水迷宫实验中,与正常组相比,8周中等负荷游泳干预后,大鼠第1 d的平均逃避潜伏期降低(P<0.01),平均穿越原站台位置次数增加(P<0.05);8周高度负荷游泳训练后,大鼠平均穿越原站台位置次数减少(P<0.05)。real time RT–PCR和Western Blot实验测试发现,与正常组对比,中等负荷游泳干预后,大鼠小脑NCAM mRNA和蛋白表达均升高(P<0.05,P<0.05);然而高度负荷游泳训练后,大鼠小脑NCAM mRNA和蛋白表达未出现明显降低(P>0.05,P>0.05)。结论:长期中等适宜强度运动改善大鼠学习和记忆能力的可能机制是小脑NCAM表达量的调高;在大强度运动中,大鼠空间记忆能力出现衰退,而小脑NCAM表达量和空间学习能力并未受到影响。

Objective:To investigate the possible mechanism of exercise intervention on learning and memory ability of rats’cerebellum by constructing the different loads models of swimming exercise,and observing the expression of neural cell adhesion molecule(NCAM)in cerebellum of rats.Methods:Two-month-old male SD rats were randomly divided into three groups,including control group(control,n=10,an 8-week normal feeding),moderate-load training group(MT,n=10,an 8-week moderate load swimming exercise)and high-load training group(HT,n=10,8 weeks by high load swimming exercise).The spatial learning and memory ability of rats were detected by Morris water maze.The serum testosterone levels of rats were measured with ELISA in three groups.The expression of NCAM mRNA and protein in rats’cerebellum were measured with real time RT-PCR assay and Western Blot assay.Results:Morris water maze experiment showed that after 8 weeks of moderate-load swimming exercise intervention,the average escape latency on the 1st day was significantly shorter than that of control group(P<0.01),and the average number of crossing platform was significantly higher(P<0.05);After the 8-week high-load swimming exercise,the average number of crossing platform was significantly lower(P<0.05).Moreover,real time RT-PCR assay and Western Blot assay showed that compared with the control group,the expression of NCAM mRNA and protein in cerebellum of rats were higher after the moderate-load swimming exercise intervention(P<0.05,P<0.05);However,after the high-load swimming exercise,there was no significant decrease in the expression of NCAM mRNA and protein(P>0.05,P>0.05).Conclusion:Our work demonstrated that long-term moderate load exercise can improve the spatial learning and memory ability of rats,and the molecular mechanism may be the high expression of NCAM in the cerebellum.The spatial memory ability of rats was decreased in the long-term excessive load exercise,however,the expression of NCAM in the cerebellum and spatial learning ability were not affected.