经颅磁刺激对脑梗死大鼠神经功能恢复与皮层BDNF表达的影响

The effects of transcranial magnetic stimulation (TMS) on recovery of neural functions and expression of BDNF in cerebral cortex of rats after cerebral infarction

目的研究经颅磁刺激(transcranial magnetic sti mulation, TMS)对脑梗死大鼠神经功能恢复和皮层脑源性神经营养因子(Brain derived neurotrophic factor , BDNF)表达的影响。方法成年健康雄性SD大鼠80只,随机分为脑梗死1、7、14、21、28d组及TMS1、7、14、21、28d组,每组各8只;采用线栓法制作左侧大脑中动脉闭塞的脑梗死模型;在规定的时间点行神经功能评定,应用免疫组化的方法检测梗死侧皮层BDNF的表达。结果 (1)和脑梗死28d组相比,TMS28d组大鼠Bederson神经功能评分、平衡木实验、网屏实验评分均较低,两者相比具有显著性差异(P<0.01) ;转棒实验虽评分较低,但2组无显著性差异(P>0.05) ;(2)大鼠脑梗死1d后梗死侧皮层可见较多BDNF阳性表达神经细胞,主要位于梗死灶周围,至第7d表达达高峰,然后开始下降;TMS7、14、21d组梗死侧皮层BDNF表达增加。结论 TMS能促进脑梗死大鼠神经功能恢复,机理可能与TMS能增加脑梗死侧皮层BDNF表达有关。

Objective To study the effects of transcranial magnetic stimulation （TMS） on recovery of neural functions and expression of BDNF in cerebral cortex of rats with cerebral infarction. Methods 80 male SD rats were divided into cerebral infraction 1,7,14,21 and 28d group and TMS 1,7,14,21 and 28d group randomly （n = 8）. The rat models of focal cerebral infarction were established with unilateral middle cerebral artery （MCA） suture occlusion method. The neural functions were evaluated and the expression of BDNF in ipsilateral infarction cerebral cortex was detected by using histochemistry technique. Results （1） To compare with cerebral infacrtion 28 d group, the scores of Bederson neural function, balance wood test and grid curtain test were lower in TMS 28 d group （P〈0. 05）. The score of rolling poll test was lower in TMS 28 d group than in cerebral infarction 28 d group （P〉0. 05）. （2） Many BDNF positive reaction neural cells appeared in cortex of infarction side brain on 1 day after cerebral infarction and lied mainly around the infarction focus, peaked on 7th day, then decreased. TMS enhanced the expression of BDNF in the ipsilateral infarction cerebral cortex of rats in TMS 7,14,21 d group. Conclusions TMS can promote the recovery of neural functions of rats with cerebral infarction. This may be associated with enhancement of the expression of BDNF in the cerebral cortex by TMS.