长期小强度跑台运动对C57BL/6J小鼠突触可塑性的影响

Effects of low intensity treadmill training on synaptic plasticity in C57BL/6J mice

目的:本研究观察长期小强度跑台运动对C57BL/6J小鼠突触可塑性的影响,探讨运动提高学习和记忆能力的细胞机制。方法:3月龄雌性C57BL/6J小鼠随机分为运动组(12只)和对照组(12只)。运动组小鼠进行5个月小强度跑台训练,运动训练结束后进行Morris水迷宫检测学习和记忆行为学改变,1周后采用电生理学方法在体记录海马齿状回(DG)的群体峰电位(PS)和场兴奋性突触后电位(f-EPSP)的变化。电生理学测试后制备小鼠脑石蜡切片,采用免疫组织化学方法检测海马DG区突触素(SYP)的蛋白表达情况,并取海马组织利用Western blot方法检测SYP的蛋白表达。结果:电生理学结果显示,高频刺激后运动组小鼠PS幅值和f-EPSP斜率百分数均高于对照组,差异具有显著性(P<0.05);运动组小鼠海马组织突触素蛋白表达水平明显高于对照组,差异具有显著性(P<0.05);运动组小鼠海马齿状回突触素阳性反应产物的整合光密度值明显高于对照组,差异具有显著性(P<0.05)。结论:5个月小强度跑台运动可增强C57BL/6J小鼠的突触结构和功能可塑性。

Objective:To investigate the effects of low intensity treadmill training on synaptic plasticity in C57BL/6J mice,and to elucidate the underlying cellular mechanism involved in exercise-induced learning and memory improvement.Method:At three months of age,female C57 mice were randomly assigned into control group(Con,N=12)and exercised group(Exe,N=12).After 5-months treadmill exercise,electrophysiology studies were carried out.Population spike(PS)and field-excitatory postsynaptic(f-EPSP)in dentate gyrus were recorded.6 brains of each group were embedded in paraffin for immunohistochemistry.6 hippocampi were prepared for Western blot analysis.The protein expression of Synaptophysin was observed.Result:After HFS,compared with control group,the exercised mice showed increased PS and f-EPSP(P<0.05).SYP protein levels were up-regulated in the hippocampus of the Exe mice when compared with Con mice(P<0.05).The results of immunohistochemical staining showed a notably increased expression of Synaptophysin in dentate gyrus of the exercised mice(P<0.05).Conclusion:5-months low intensity treadmill exercise improved synaptic plasticity in C57BL/6J mice.