运动训练对脑梗死大鼠行为学及突触形态结构参数的影响

Effects of motor training on behavior and synaptic structures morphology in cerebral infarction rats

目的:研究运动训练对脑梗死大鼠行为学的影响并从突触形态结构可塑性角度探讨其机制。方法:用线栓法制作大鼠大脑中动脉脑梗死(MCAO)模型,32只Wistar大鼠随机分为模型组和康复组。康复组于手术后第5d开始进行滚筒、转棒、走平衡木、网屏训练,对大鼠进行运动能力和学习记忆能力测评观察其行为学变化,电镜观察缺血侧感觉运动区和CA3区突触形态结构的变化。结果:第5周时康复组和模型组转棒活动、平衡木活动、网屏训练比较差异有显著性意义(P<0.05),学习记忆能力比较康复组与模型组差异有非常显著性意义(P<0.01)。康复组两脑区(患侧感觉运动皮质和海马CA3区)突触界面曲率、突触活性区长度增加,与模型组比较差异有显著性意义(P<0.05).PSD厚度和穿孔性突触百分率明显增加,与模型组比较差异有非常显著性意义(P<0.01)。结论:运动训练促进脑梗死大鼠运动能力和学习记忆能力的恢复,其机制可能与脑梗死大鼠缺血侧感觉运动皮质和海马CA3区突触结构参数改变有关。

Objective： To study the changes of behavior and synaptic structures morphology in cerebral infarction rats after motor training.To discuss the mechanism of behavior rehabilitation and plasticity of synaptic structures in cerebral infarction. Method：An animal model was made by occlusion of the middle cerebral artery （MCAO）. Thirtytwo 2-month old male Wistar rats were divided into the rehabilitation group and the model group randomly. Motor training （balancing,grasping,rotating and walking exercises） were applied to the rats of the rehabilitation group at the 5th day post operation （40mirdd and 6 times per week） , while those in the model group were reared in their original living state. Rotating bar activity balancing wood activity, and net screen were tested at the 5th week after operation. The stuctures morphology of synapse in sensory-motor cortex and hippocampus CA3 area at ischemia side were observed under electronmicroscope. Result：Motor ability of rehabilitation group was better than that of the model group. Compared with the model group, rotating bar activity,balancing wood activity and net screen test of the rehabilitation group were significant different at 5th week（P〈0.05）. Both learning and memory abilities were improved in those rats following the motor training（P〈0.01）. The synaptic curvatures and the synapse length of the active area improved obviously in the rats of rehabilitation group in contrast to those of model group （P〈0.05）.The post-synaptic density （PSI）） and percentage of perforated synapses increased significantly in the rats of rehabilitation group in comparison to those of model group （P〈0.01）. Conclusion：Motor training can promote recovery of cerebral infarcted neural function,ability of motor learning and memory in rats,which are likely to be related to the synaptic changes in sensory-motor cortex and the hippocampus CA3 area and increased synaptic plasticity.