神经肌肉电刺激对大鼠脑梗死周围区PI3K信号通路介导的神经元极性重建的影响

Neuromuscular electrical stimulation(NMES) has been proved clinically in improving motor function of the hemiplegic limbs in patients with stroke. Our prevous basic study has demonstrated that NMES is effective in promoting the motor function of the rats with cerebral infarction and in enhancing the expression of Microtubule associated protein-2 and Synaptophysin in the surrounding area of cerebral infarction. It is not known that which signal pathway mediates NMES in improving the cerebral plasticity. Neuronal polarity reestablishment mediated by the PI3K signal pathway plays an important role in the cerebral plasticity. This study is up to treating the rats of cerebral infarction obtained by the middle cerebral artery occlusion with NMES. After that, the morphology of the synapse in the surrounding area of the cerebral infarction is observed by the electronic microscope and the major regulatory proteins Akt, GSK3βand MARK2 in the PI3K pathway are detected by immunohistochemistry, RT-PCR and Western Blot methods. All of the above indicators are detected again after applying the inhibitor LY294002 of PI3K. This study will investigate wether NMES can enhance the neuronal polarity reestablishment mediated by the PI3K signal pathway. The study will further define the moleculor mechanism of NMES and give the basis for clinical application.

临床研究证实神经肌肉电刺激（NMES）可以改善脑卒中患者的肢体功能，本课题组已完成的基础研究也证实NMES可以改善脑梗死大鼠的运动功能，并促进脑梗死周围区微管相关蛋白-2、突触素等蛋白表达增强，即促进脑的可塑性，但NMES是通过何种信号通路促进脑的可塑性尚未见相关报道。由磷脂酰肌醇3激酶（PI3K）信号通路所介导的神经元极性重建过程在脑的可塑性中起着重要作用，因此本研究拟应用NMES治疗大脑中动脉栓塞脑梗死大鼠，以电子显微镜技术观察脑梗死周围区突触形态学变化，以免疫组化、荧光定量RT-PCR、Western Blot技术检测PI3K通路上关键调节蛋白Akt、GSK3β、MARK2表达变化，并应用PI3K阻滞剂LY294002后，再次观察上述指标的变化，以证实NMES是否通过PI3K通路来介导神经元的极性重建。本研究可以进一步阐明NMES治疗的分子机制，为其临床应用进一步提供重要的的理论依据