重复经颅磁刺激对脊髓损伤大鼠运动功能的影响

关键词：重复经颅磁刺激  脊髓损伤  运动诱发电位  神经丝蛋白

Keywords:repetitive transcranial magnetic stimulation  spinal cord injury  motor evoked potentials  neurofilament protein

摘要：

      摘要 目的：研究重复经颅磁刺激（rTMS）对脊髓损伤大鼠运动功能的影响并探讨其可能机制。 方法：48只SD大鼠随机分为正常对照组、脊髓损伤对照组、脊髓损伤高频磁刺激组、脊髓损伤低频磁刺激组，每组各12只。利用重物撞击法制作T10脊髓损伤模型。磁刺激组于手术后24h开始给予刺激，高频组频率为10Hz，低频组频率为1Hz，均为阈上（120%阈值）刺激，500个脉冲，每日1次，连续8周，脊髓损伤对照组给予假刺激。分别于术后第1天及连续8周每周进行1次BBB行为学评分、检测运动诱发电位（MEP），并于第2周、第4周、第8周处死部分大鼠后应用HE染色观察脊髓组织形态学变化、应用免疫组织化学法检测神经丝蛋白（NF-200）表达的变化。 结果：正常组BBB评分高于脊髓损伤各组，治疗组BBB评分高于脊髓损伤对照组，高频组BBB评分高于低频组，差异均有显著性意义（P<0.035）；脊髓损伤治疗组运动诱发电位检出率高于对照组，低于正常组（P<0.043）；神经丝蛋白表达脊髓损伤磁刺激组较对照组明显升高，差异有显著性意义（P<0.020），高频组较低频组高，P<0.020。 结论：重复经颅磁刺激可以促进脊髓损伤大鼠运动功能的恢复，其机制可能与促进轴突再生有关。

Abstract:

      Abstract Objective: To investigate the effects of repetitive transcranial magnetic stimulation(rTMS) on locomotor function of rats with spinal cord injury(SCI) and its mechanism. Method: Weight drop SCI model was made at T10 segment with modified impactor device. Forty-eight rats were randomly divided into four groups: high frequency rTMS group, low frequency rTMS group, SCI control group and normal control group. Stimulation group received up-threshold(120%) rTMS daily for 8 weeks. Basso Beatti and Bresnahan(BBB) locomotor scores were recorded weekly. Motor evoked potential(MEP) was detected once weekly, Neurofilament-200(NF-200) was detected with immunofluorescence staining in SCI lesion at the 2nd, 4th and 8th week respectively. Result: The BBB scores in stimulation groups improved compared with that in SCI control group(P＜0.035). The detected rates of MEP in stimulation groups were higher than that in SCI control group(P＜0.043). NF-200 markers up-expressed in stimulation groups(P＜0.020). Conclusion: rTMS can improve the locomotor function of rats with incomplete SCI, which may result from up-expression of NF-200.