重复经颅磁刺激对大鼠缺血脑组织中突触素表达及运动功能康复的影响

目的探讨重复经颅磁刺激(rTMS)对脑可塑性的影响及其作用机制。方法雄性SD大鼠96只,随机分为模型组、假刺激组、急性期rTMS组和慢性期rTMS组,每组24只;采用线栓法制备大鼠右侧大脑中动脉闭塞的脑缺血再灌注模型。分别于建模后6、13、27 d时用免疫组织化学方法检测大鼠梗死侧皮质突触素的表达,同时评价大鼠神经功能。电镜观察大鼠梗死侧皮质突触损害情况。结果与模型组比较,急性期rTMS组梗死侧皮质突触素阳性细胞数在再灌注6、13、27 d明显增多,神经功能障碍评分在再灌注6、13 d明显增高,慢性期rTMS组梗死侧皮质突触素阳性细胞数在再灌注13、27 d明显增多,神经功能障碍评分在再灌注13 d明显增高(1 3.63±1.06)分vs(11.88±1.25)分,P<0.05,P<0.01]。电镜观察,急性期rTMS组和慢性期rTMS组梗死侧皮质突触损害程度较模型组相对较轻。结论 rTMS使脑缺血再灌注损伤后大鼠梗死侧皮质的突触素阳性细胞数目有不同程度的增加;rTMS对脑缺血再灌注损伤后大鼠的神经功能恢复有一定程度的促进作用。

Effect of rTMS on expression of synaptophysin and recovery of motor function in rats with cerebral infarction

Objective To study the effect of repetitive transcranial magnetic stimulation(rTMS) on expression of synaptophysin(SYN)and recovery of motor function in rats with cerebral infarction and its mechanism.Methods Ninety-six male SD rats were randomly divided into model group, sham stimulation group,acute rTMS group and chronic rTMS group(24 in each group).A cerebral ischemia/reperfusion(I/R) injury model was established.Expression of SYN in infarction cortex was detected with immunohistochemistry on days 6,13,and 27 after the model was established. Nerve function in rats was assessed.Synaptic damage in the infarction cortex was observed under electron microscope.Results The number of SYN positive cells in the right infarction cortex was significantly higher in acute rTMS group than in model group on days 6,13,and 27 after I/R inury.The nerve dysfunction score was significantly higher in acute rTMS group than in model group on days 6 and 13 after I/R inury.The number of SYN positive cells in the right cortex was significantly higher in chronic rTMS group than in model group on days 13 and 27 after I/R inury.The nerve dysfunction score was significantly higher in chronic rTMS group than in model group on day 13 after I/R inury(l.88±1.25 vs 3.63±1.06,P<0.05).Electron microscopy showed that the synaptic damage in the right infarction cortex was milder in acute and chronic rTMS groups than in model group.Conclusion rTMS promotes recovery of nerve function in rats after I/R inury by increasing the number of SYN positive cells in the infarction cortex.