中等强度游泳运动对海马突触可塑性的调节

Regulation of Moderate Intensity Swimming Exercise on Hippocampal Synaptic Plasticity

目的:探索中等强度游泳运动对海马突触可塑性影响的时效性及延续性特点。方法:雄性SD大鼠48只,随机分为对照组(CG)、3天运动组(3D)、7天运动组(7D)、15天运动组(15D)、5周运动组(5W)、5周运动后延迟1周组(P5W),利用免疫荧光、电镜、Western blot技术分别对各组大鼠海马组织进行细胞增殖、突触可塑性、突触结构蛋白表达的检测。结果:CG、3D、7D、15D、5W、P5W组大鼠海马齿状回颗粒细胞下层细胞增殖率(%)分别为31.70±1.57、40.19±2.40、36.74±4.06、51.70±5.93、52.90±6.10、51.97±1.47,15D、5W、P5W组大鼠细胞增殖率均显著性高于对照组(P<0.05);5W、P5W组突触数目、PSD厚度显著性高于CG组(P<0.05,P<0.001),5W、P5W组的突触间隙宽度显著性小于CG组(P<0.05,P<0.001),15D组PSD厚度显著性高于CG组(P<0.05);海马结构蛋白MAP2的表达5W组、P5W组显著性高于CG组(P<0.05,P<0.001),15D、5W、P5W组SYP的表达显著性高于CG组(P<0.05)。结论:中等强度游泳运动诱导的海马可塑性变化具有运动时间依赖性;运动诱导的突触可塑性变化在停止运动后还具有延续性。

Objective： To explore the timeliness and continuity characteristics about the influence of moderate intensity swimming on hippocampal synaptic plasticity. Methods： 48 male SD rats were randomly divided into control group（CG）, 3 days（ 3 D）, 7 days（ 7 D）, 15 days（15 D）, 5 weeks（ 5 W） exercise groups and 1 week delayed group after 5 weeks exercise（ P5W）. Immunofluorescence, electron microscopy and Western blot technology were used to detect the cell proliferation, synaptic plasticity and synaptic structure associated protein expression respectively in the hippocampal tissue of different swimming rat groups. Results： The proliferation rate（%） of hippocampal dentate gyrus granular cell were 31.70± 1.57, 40.19± 2.40, 36.74± 4.06, 51.70±5.93, 52.90± 6.10, 51.97± 1.47 of CG, 3 D, 7 D, 15 D, 5 W, P5W group respectively, the proliferation rate of 15 D, 5 W, P5W groups were significantly higher than that of control group（P〈0.05）. The synapse numbers and PSD thickness of 5 W, P5W groups were significantly higher than that in CG group（P〈0.05 or P〈0.001）, the synaptic cleft width of 5 W, P5W groups was significantly lower than that in CG group（P〈0.05 or P〈0.001）, the PSD thickness of 15 D group was significantly higher than that of CG group（P〈0.05）. The expression of hippocampal structural protein MAP2 in 5 W, P5W groups was significantly higher than that in CG group（P〈0.05 or P〈0.001）, and the expression of SYP in 15 D, 5 W, P5W groups was significantly higher than that in CG group（P〈0.05）. Conclusions： The hippocampal plasticity induced by moderate intensity swimming has time dependent characteristic and the synaptic plasticity induced by exercise has continuity after the cessation of exercise.