有氧训练对阿尔茨海默病模型大鼠海马神经细胞凋亡及再生的影响

Effects of Aerobic Training on the Apoptosis of Neuron and Neuroregeneration in the Hippocampus of Alzheimer's Disease Model Rats

目的:观察有氧训练对Aβ_(25-35)诱导的阿尔茨海默病(AD)大鼠海马神经细胞凋亡及再生的影响。方法:SD大鼠48只,随机分为3组(均n=16):①假手术组(于大鼠侧脑室注射等量生理盐水+4周有氧训练);②AD+有氧训练组(于大鼠侧脑室注射Aβ_(25-35)制作AD大鼠模型+4周有氧训练);③AD组(仅于大鼠侧脑室注射Aβ_(25-35)制作AD模型)。AD造模后第3天开始进行连续4周的无负重游泳训练,训练结束后各组大鼠分别行Morris水迷宫行为学检测认知行为能力、Hoechst染色观察海马神经细胞凋亡、BrdU/NeuN荧光双染观察齿状回(DG)区新生神经细胞分化及成熟。结果:①Morris水迷宫实验显示,与对照组相比,AD组逃避潜伏期显著延长(P<0.05);AD+有氧训练组逃避潜伏期较AD组显著缩短(P<0.05)。②与对照组比,AD组齿状回区Hoechst阳性细胞显著增多(P<0.05);AD+有氧训练组Hoechst阳性细胞较AD组显著减少(P<0.05)。③与对照组比,AD组齿状回Brdu、Brdu/NeuN双染阳性细胞明显减少(P<0.05);AD+有氧训练组较AD组相比齿状回Brdu、Brdu/NeuN双染阳性细胞明显增多(P<0.05)。结论:有氧训练后,AD大鼠海马亚颗粒细胞区神经细胞的凋亡减少,齿状回神经再生增加,上述改变可能为有氧训练改善AD大鼠认知行为能力的机制之一。

Aim： To observe the effects of aerobic trainings on the apoptosis of neuron and neuroregeneration in the hippocampus of Alzheimer＇ s disease（AD） rats. Methods： 48 SD rats were divided into three groups randomly： sham-operated group, AD ＋ aerobic trainings group and AD group. Then all rats were tested in morris water maze. The apoptosis of neuron was observed by Hoechst staining in the subgranular zone（SGZ）. The differentiation and maturation of newborn neurons were individually examined by BrdU staining and BrdU/NeuN-staining in the dentate gyrus（DG） zones. Results： ① In the Morris water maze test, latency to find a kidden platform in AD group was longer than that of the sham-operated group（P〈0.05）. Compared with AD group, the escape latency in AD ＋ aerobic trainings group was shorter（P〈0.05）. ② Compared with the sham- operated group, Hoechst positive cells increased in the AD group. There was a decreasing Hoechst positive cells in AD ＋ aerobic trainings group compared with the AD group（P〈0.05）. ③ Compared with the sham- operated group, BrdU/NeuN positive cells decreased in the experimental group. There were increasing BrdU/ NeuN positive cells in AD ＋ aerobic trainings group compared with the AD group in the DG（P〈0.05）. Conclusion： After aerobic trainings for four weeks, the apoptosis of neuron in SGZ was decreasing, accompanied by the increasing of neuroregeneration in DG, which indicated that the changes above might be one of the mechanism that regular aerobic trainings improve the cognitional ability in AD rats.