有氧运动干预对衰老大鼠学习记忆能力及小脑生长相关蛋白-43表达的影响

Effects of aerobic exercise intervention on learning and memory ability and expression of GAP-43 in cerebellum of aging rats

目的:探讨衰老过程中进行有氧运动干预对大鼠学习记忆能力及小脑神经生长相关蛋白-43(growth associated protein-43,GAP-43)表达的影响。方法:45只成年雄性SD大鼠随机分为生理盐水对照组(Na组,n=15)、有氧运动干预组(S组,n=15)和衰老对照组(N组,n=15)。S组进行6周的衰老造模同时进行有氧运动干预,N组大鼠进行6周的衰老造模,Na组大鼠注射6周的生理盐水进行对照实验。三组大鼠造模结束后分别进行7天的Morris水迷宫实验测试大鼠的学习记忆能力,Morris水迷宫结束后24h内取大鼠的小脑,利用实时PCR法检测小脑内GAP-43 mRNA表达水平,Western-blotting法检测小脑GAP-43蛋白含量。结果:Morris水迷宫定位航线实验当中:第2天和第1天相比,第3天和第2天相比,Na组、N组和S组大鼠平均潜伏期均缩短且存在显著性差异(P<0.01);第4天和第3天相比,N组大鼠平均潜伏期存在显著性差异(P<0.01),Na组和S组平均潜伏期无显著性差异(P>0.05);第5天和第4天相比,第6天和第5天相比,Na组、N组和S组大鼠平均潜伏期无显著性差异(P>0.05)。Morris水迷宫空间探索实验结果显示:Na组和S组穿越原平台位置次数多于N组且存在显著性差异(P<0.01)。实时PCR实验和Western-blotting结果显示:Na组和S组大鼠小脑内GAP-43表达量皆高于N组大鼠且存在显著性差异(P<0.01)。结论:在衰老过程中进行有氧运动干预在一定程度上可以促进脑衰老大鼠的学习记忆能力和小脑内GAP-43的表达,这可能是有氧运动延缓脑衰老学习记忆能力下降的分子机制之一。

Objective: To investigate the effects of aerobic exercise intervention on learning and memory ability and expression of growth associated protein-43(GAP-43) in the cerebellum in aging rats.Method: Forty-five male adult SD(Sprague-Dawley) rats were randomly divided into normal saline control group(Na group, n=15), aerobic exercise intervention group(S group, n=15) and aged control group(N group,n=15). Group S performed 6 weeks of aging modeling while performing aerobic exercise intervention,Group N rats were subjected to aging modeling for 6 weeks, and Na group rats were injected with physiological saline for 6 weeks for control experiments. Rats’ learning and memory ability was tested by Morris water maze for 7 days after the completion of each model. Rat’s cerebellum was taken within 24 hours after Morris water maze was completed. The expression of GAP-43 mRNA in cerebellum was detected by real-time PCR, and the content of GAP-43 protein in cerebellum was measured by Western-blotting method.Result: In the Morris water maze locator route experiment, compared to the second day and the first day, compared to the third day and the second day, the average latency of the Na group, the N group and the S group was shortened and there was a significant difference(P<0.01);compared with the fourth day and the third day, the average latency of group N was significantly different(P<0.01), and there was no significant difference in average latency between group Na and group S(P>0.05);compared to the fifth day and the fourth day, compared to the sixth day and the fifth day, there was no significant difference in the average latency between the Na group, the N group, and the S group(P>0.05). The Morris water maze space exploration experiment results show that: Na group and S group crossing the original platform position more than N group and there is a significant difference(P<0.01). Real-time PCR and Western-blotting results showed that the expression of GAP-43 in the cerebellum of Na group and S group was higher than that of N group rats and there was a significant difference(P<0.01).Conclusion: Aerobic exercise intervention during the aging process can promote the learning and memory ability and the expression of GAP-43 in the cerebellum of rats in a certain extent, which may be one of the molecular mechanisms of aerobic exercise retarding the decline of learning and memory abilities of brain aging.