电针百会、神庭对大脑中动脉栓塞大鼠学习记忆功能和前额叶皮层GABAA受体及PSD-95表达的影响

Effects of electroacupuncture on Baihui and Shenting on learning and memory function and expression of GABAA receptor and PSD-95 in the prefrontal cortex of MCAO rats model

目的:观察电针百会、神庭对MCAO大鼠学习记忆功能及前额叶皮层γ-氨基丁酸A型(gamma-aminobutyric acid,GABAA)受体及突触后密度蛋白-95(postsynaptic density protein-95,PSD-95)表达的影响,探讨电针对MCAO大鼠学习记忆功能的影响及作用机制。方法:改良Longa线栓阻塞法制备左侧大脑中动脉栓塞(middle cerebral artery occlusion,MCAO)模型,将造模成功的雄性Sprague-Dawley大鼠随机分成模型组、电针组(百会、神庭)和电针非穴组,同时另设假手术组,每组10只。电针组和非穴组进行连续7d电针干预,假手术组和模型组不做任何处理。采用小动物磁共振成像仪检测干预前后大鼠脑梗死体积变化;Morris水迷宫评价大鼠学习记忆功能;HE染色观察缺血侧前额叶皮层病理变化;Western Blot法检测缺血侧前额叶皮层GABAA受体及PSD-95蛋白表达水平。结果:干预前各组大鼠脑梗死体积无显著性差异(P>0.05),随着干预时间延长,与模型组和非穴组相比,电针组行为学评分明显降低(P<0.05);电针组Morris水迷宫学习记忆测试逃避潜伏期缩短(P<0.05)。干预后,与模型组和非穴组相比,电针组脑梗死体积明显减小(P<0.01);电针组神经元密度和神经细胞数量明显增加;电针组前额叶皮层GABAA受体及PSD-95蛋白表达均明显上升(P<0.05),而模型组和非穴组之间无明显差异(P>0.05)。结论:电针百会、神庭能有效减轻脑缺血后神经损伤,改善学习记忆功能,可能与增加其前额叶皮层神经元数量,促进GABAA受体及PSD-95表达有关。

Objective:To observe the effect of electroacupuncture on Baihui and Shenting on learning and memory function and the expression of gamma-aminobutyric acid(GABAA)receptor and postsynaptic density protein-95(PSD-95)in the prefrontal cortex of middle cerebral artery occlusion(MCAO)rats model,and to explore the effect and mechanism of electroacupuncture on learning and memory function of MCAO rats.Method:The left middle cerebral artery occlusion model was established with the modified Longa methods.Male Sprague-Dawley rats with successful modeling were randomly divided into four groups:the model group,the electroacupuncture group(Baihui,Shenting),the electroacupuncture non-acupoint group,and the sham operation group,with 10 rats in each group.The electroacupuncture group and the non-acupoint group received electroacupuncture intervention for 7 consecutive days,and the sham operation group and the model group did not receive any treatment. MRI was used to detect the changes of cerebral infarction volume before and afterintervention;the Morris water maze was used to evaluate the learning and memory function of rats;HE stainingwas used to observe the pathological changes of the ischemic prefrontal cortex;and Western Blot wasused to detect the ischemic prefrontal cortex γ-aminobutane expression levels of GABAA receptors and PSD-95proteins.Result:Before the intervention, there was no significant difference in the volume of cerebral infarction betweenthe groups (P>0.05). Compared with the model group and the non-acupoint group,the behavioral scoreof the electroacupuncture group was significantly lower with the prolongation of the intervention time(P<0.05).In the electroacupuncture group, the escape latency of the Morris water maze learning and memory test wasshortened (P<0.05). After intervention,the volume of cerebral infarction in the electroacupuncture group wassignificantly reduced compared with the model group and the non-acupoint group(P<0.01);the density of neuronsand the number of nerve cells in the electroacupuncture group were significantly increased;the GABAA receptorsin the prefrontal cortex of the electroacupuncture group were significantly increased, and PSD-95 proteinexpression was significantly increased (P<0.05),but there was no significant difference between the modelgroup and the non-acupoint group (P>0.05).Conclusion:Electroacupuncture of Baihui and Shenting can effectively reduce nerve injury after cerebral ischemiaand improve learning and memory function,which may be related to increasing the number of neuronsin the prefrontal cortex and promoting the expression of GABAA receptors and PSD-95.