经颅磁刺激帕金森病模型大鼠运动皮质兴奋性的研究

The study of Cortical threshold of Motor evoked potentials by transcranial magnetic stimu- lation for model rats of Parkinson^s disease

目的：探讨经颅磁刺激（transcranialmagneticstimulation，TMS）对帕金森病（Parkinsondiscase，PD）模型大鼠大脑皮质电生理学的影响，并从电生理角度探讨PD的发病机制。方法：实验分两组，健康SD雄性大鼠40只，随机分为2组：①实验组（PD模型组）26只，②对照组（生理盐水组）14只。采用静息皮层运动阈值（RMT）、中枢传导时间（CMCT）和运动诱发电位（MEP）的波幅（Amp）作为评定大脑皮质兴奋性的指标。结果统计采用SPSS]1．5统计软件处理，P〈0．05为差异有显著意义。结果：术后1周，实验组左下肢RMT、CMCT较对照组降低或缩短（P〈O．05），而Amp无明显变化；实验组自身左右侧比较，左下肢RMT、CMCT较右下肢缩短，Amp增高（P〈0．05）；制模前、术后1周、术后3周实验组大鼠左下肢RMT、CMCT进行性降低（P〈0．05）；实验组大鼠右下肢与对照组大鼠左侧及右侧下肢RMT、CMCT及Amp比较差异无统计学意义（P〉0．05）。结论：PD模型大鼠损毁侧皮层兴奋性增加，且与症状严重程度相关；PD模型大鼠病情越重、病程越长，大脑皮层兴奋性升高更明显。

Objective： To explore the effect of transcranial magnetic stimulation on the excitability with the motor rats with Parkinson’s disease（PD） and to research the mechanism of PD from the electro physiology. Methods：Rats were randomly divided into the experimental group （n： 26） and the control group （n=14）. Excitability of the motor cortex was assessed by rest motor threshold（RMT）, central motor conduction time（CMCT）and amplitude of motor evoked potential（MEP）. Statistical analysis was performed by using SPSS 11. 5 software. Results： A week after operation, the motor rats of left lower limb were treated by TMS, the results of RMT, CMCT was significantly low in the experimental group （P〈0.0S） as compared with the control group, but Amp amplitudes were not changed. In the experi- mental group,RMT and CMCT of left lower limb significantly lower than right（P〈0.05） ,Three weeks after operation,RMT and CMCT of left lower limb were significantly low in the experimental group（P〈 0.05） as compared with the control group, And RMT,CMCT and Amp of left lower limb significantly lower than right ones （P〉0.05）. Conclusion： Our study reveals that the cortex excitability increases and the excitability is higher with the more serious symptom side. The worse the disease get and the longer the course of disease is in PD model rats, the more obviously the cortex excitability obviously increased.