电针改善坐骨神经损伤大鼠步行能力及跨半球可塑性机制研究

A study on electro-acupuncture improving the walking ability of rats with sciatic nerve injury via modulating interhemispheric plasticity

目的:采用静息态fMRI体素-镜像同伦连接(VMHC)和Granger因果分析(GCA)方法,探讨电针改善坐骨神经损伤大鼠步行能力的作用及跨半球可塑性机制。方法:16只右侧坐骨神经横断外膜缝合模型大鼠,随机等分为治疗组和对照组。治疗组予电针治疗,对照组无特殊干预。于术后1月、4月行步态分析和静息态fMRI扫描。结果:治疗组术后1月、4月步态分析最大接触平均强度均较对照组显著提高(P<0.05)。术后1月两组VMHC差异无显著性,术后4月治疗组运动皮质、杏仁核、嗅皮质VMHC较对照组显著降低(FDR校正,P<0.01)。GCA结果显示术后4月治疗组大鼠左侧运动皮质到右侧运动皮质的效应连接较对照组显著降低(P<0.05)。结论:电针治疗可以改善坐骨神经损伤大鼠的步行能力,可能与电针调节了大鼠半球间功能连接和定向效应连接有关。

Objective:To investigate the effect of electro-acupuncture on walking ability of rats with sciatic nerve injury and the mechanism of interhemispheric plasticity by voxel-mirrored homotopic connectivity(VMHC)and Granger causal analysis(GCA)based on rest-stating fMRI.Method:Sixteen rats of sciatic nerve transection and direct anastomosis were divided into 2 groups randomly:intervention group and control group.Rats of intervention group were treated by electro-acupuncture.Catwalk gait analysis and rest-stating fMRI were performed 1 month and 4 months after surgery.Result:The gait parameters max contact mean intensity(MCMI)of the intervention group was significantly higher than the control group(P<0.05)at 1 and 4 months after surgery.4 months after surgery,the motor cortex,entorhinal cortex and amygdala of intervention group showed significantly lower VMHC compared with the control group.However,there was no significant difference of VMHC between two groups 1 month after surgery.Results of GCA showed that the intervention group exhibited an significantly lower signed-path coefficient from left motor cortex to right motor cortex compared with the control group 4 months after surgery.Conclusion:Electro-acupuncture could improve walk ability of sciatic nerve injury rats,which might be due to the modulation of interhemispheric functional connectivity and directed effective connectivity.