帕金森病模型大鼠经颅磁刺激运动诱发电位皮层阈值的研究

Study of Cortical threshold of Motor evoked potentials by transcranial magnetic stimulation for model rats with Parkinson disease

目的:通过对帕金森病(Parkinson disease,PD)模型大鼠经颅磁刺激(transcranial mag-netic sti mulation,TMS)运动诱发电位(MEP)皮层阈值(cortical threshold,Ct)的研究,以明确PD的Ct测值以及随病情发展的变化情况,以期为PD临床提供电生理学实验研究依据。方法:实验动物为健康的Sprague-Dawley(SD)雄性大鼠40只,随机分为两组:①实验组(PD模型组)28只;②对照组(生理盐水组)12只。选取其右侧中脑黑质致密部(substantia nigra pars compacta,SNc)与腹侧被盖(ventra teg-mental area,VTA)作为靶点,实验组注射6-羟基多巴胺(6-OHDA)以制备PD动物模型,对照组注射同等体积的生理盐水用于比较,于制模前、制模后1周、3周分别行双下肢记录的Ct检查。结果统计采用SPSS11.5统计软件处理,P<0.05为差异有显著意义。结果:术后1周,实验组在右侧中脑靶点TMS时于左下肢记录到的Ct较对照组降低,具有统计学意义(P<0.05),实验组自身左右侧TMS-MEP比较,左下肢Ct较右下肢降低(P<0.05);制模前、术后1周、术后3周实验组大鼠左下肢Ct进行性降低(P<0.01);实验组大鼠右下肢及对照组大鼠左侧及右侧下肢Ct比较差异无显著意义(P>0.05)。结论:PD模型大鼠损毁侧Ct增加,PD模型大鼠病情越重、病程越长,Ct增加越明显。

Objective：To make clear if Parkinson disease（PD）has cortical threshold（Ct） of transcranial magnetic stimulation-motor evoked potential（TMS-MEP） abnormality and if Ct changes with the developing state of illness. Methods： Rats were randomly assigned into either the experimental group （n 28） or the control group （n 12）, The operated target was selected in right substantia nigra pars compacta （SNC） and ventra tegmental area （VTA）. SNC and VTA were injected each 2μl （4μg/μl 6-OHDA in PBS） solution of 6-OHDA in the experimental group. Saline containing 2% vitamin C with isometry was injected to the same location in the control group. Examinating Ct before operation, a week and three weeks later after operation. Statistical analysis was done with SPSS 11.5 software. Results,, A week after operation, Ct of left lower limb was significantly lowed in the experimental group （P〈0, 05） as compared with the control group, In the experimental group, Ct of left lower limb significantly lower than that of the right （P〈0.05）. Three weeks after operation, Ct of left lower limb was significantly lowed in the experimental group （P〈0.05） as compared with the control group, And Ct of lefl lower limb significantly lower than that of the right （P〈0.01）. Conclusion： The worse the illness of PD model rats becomes, the longer in the course of disease is and the more the cortex excitability increases.