毒蕈碱M2受体在脑震荡大鼠脑内的表达变化

为了探讨脑震荡(brain concussion,BC)后认知功能障碍的大鼠中枢毒蕈碱M2受体的表达变化,本实验应用金属单摆式机械打击装置复制单纯性脑震荡大鼠模型,采用免疫组织化学结合图像分析的方法,观察BC后大脑前额叶皮质(PFC)、海马CA1-CA4区、丘脑、尾壳核(CPU)、Broca斜角带垂直支(VDB)和内侧隔核(MSN)区M2受体蛋白的表达情况。结果显示:在损伤后M2受体蛋白的表达在海马CA1-CA4区出现轻微下降(P>0.05),在PFC、VDB、CPU和MSN区即刻呈轻度上升,随后又下降,但与正常组相比无显著性差异(P>0.05);在伤后1、8、24d组大鼠丘脑M2受体的表达呈明显下降,与正常对照组比较有显著性差异(P<0.05)。以上结果提示M2受体的表达在丘脑出现明显下调的改变可能与BC认知功能的改变有关。

THE EXPRESSIONAL CHANGES OF M2 ACETYLCHOLINE RECEPTOR AFTER BRAIN CONCUSSION IN RATS

To explore the expressional changes of M2 acetylcholine receptor after brain concussion(BC) in the brain of the rats which the cognation function was disorder, the brain concussion modal was induced by a metallic pendulum-striker concussive device in rats in the present study. The expression of M2 acetylcholine receptors in the prefrontal cortex(PFC), CA1-CA4 of hippocampus, thalamus, the caudatus putamen (CPU), the vertical of diagonal band nucleus of Broca (VDB) and the media septal nucleus (MSN) was studied by immunohistochemistry and image analysis. The results showed that the expression of M2 receptor in CA1-CA4 of the hippocampus declined slightly after injury (P>0.05). The expression of M2 receptor in PFC, VDB, CPU and MSN instantly increased after injury and then rapidly decreased, but no difference was found compared with the normal rats (P>0.05). In the thalamus, the expression of M2 receptor decreased significantly at 1, 8 and 24 h after injury, compared with the normal rats (P<0.05). These results suggest that the expression of M2 acetylcholine receptor which downregulate in thalamus is correlated with the changes of cognation function induced by brain concussion.