电针预处理对脑缺血后突触结构的影响

目的 探讨电针预处理对大鼠脑缺血再灌注损伤后神经元突触可塑性有无影响.方法 采用线栓法制备大鼠大脑中动脉阻塞(MCAO)模型,研究电针预处理对缺血后1 w缺血区皮层神经元突触超微结构、突触素p38、神经生长因子(NFG)的影响.结果 缺血24h和1 w时,缺血对照组和电针组神经功能评分均低于假手术组(P＜0.05),相同时间点电针组评分高于缺血组(P＜0.05).缺血1 w时,缺血对照组和电针组突触的面数密度、突触连接带面密度、突触体密度、突触后致密物质、突触间隙宽度均低于假手术组,电针组上述各参数高于缺血对照组；突触界面曲率三组间无显著差异.缺血对照组和电针组在缺血1 w时突触素p38表达明显低于假手术组,两组间无显著差异；上述两组NGF的免疫阳性细胞数明显高于假手术组,电针组高于缺血对照组.结论 电针预处理可改善大鼠脑缺血1 w后突触超微结构,NGF表达增加可能促进了神经元的突触可塑性.

Effect of electro-acupunmture preconditioning on the synaptic ultra-structure after focal ischemia in rats

Objective To investigate whether electro-acupuncture preconditioning improves the neuronal synaptie plasticity in rats after cerebral ischemia. Metlmtls Rats were randomly divided into three groups, the sham-operated group, the ischemic control （IC） group and the electro-acupuncture preconditioning （EP） group. The middle cerebral arterial occlusion model was made by thread occlusion method in the latter two groups. The neuronal behavioral scores （NBS） were evaluated at 24 h and 1 w after reperfusion. The synaptic ultra-structure of the neurons in the ischemic cortex was observed at 1 w after reperfusion. The levels of synaptophysin （p38） and nerve growth factor were measured at the same time point. Results The NBS of the rats in the IC group and EP group was lower than that of the rats in sham-operated group at beth 24 h and 1 w after reperfusion, whereas the NBS of EP group was higher than that of IC group at the same time points. Expressions of numerical density （Nv）, surface density （Sv）, volume density （Vv） and post synaptic density （PSD） in the ischemic cortex were significantly decreased after MCAO （P 〈 O. 06）. All the data of rats in the EP group were higher compared with that of IC group. The level of synaptophysin （p38） was decreased at 1 w after reperfusion, but there was no difference between EP and IC group. No difference was found in synaptic interfacial curvature among three groups. The NGF positive cells in EP and IC group were more than that in sham-operated group, and mere positive cells were seen in EP group compared with IC group. Conclusion Electro-acupuncture preconditioning protects the synaptic ultra-structure of neurons 1 w after focal cerebral ischemia in rats, and the increased expression of NGF may improve the synaptic plasticity.