局灶性脑缺血大鼠脑室下区的mGluR7的表达

Expression of mGluR7 in the Subventricular Zone in Adult Rats Following Focal Cerebral Ischemia-reperfusion

目的通过动态观察代谢型谷氨酸受体7亚型(mGluR7)在局灶性脑缺血大鼠不同再灌注时段SVZ的表达,探讨神经发生的机制。方法采用改良的线栓法制备大脑中动脉阻塞(MCAO)2h,再灌注不同时间段(6h,24h,72h,7d,14d,28d)的大鼠短暂局灶性脑缺血模型,用免疫组化方法检测mGluR7的表达。结果缺血侧SVZ(脑室下区)的mGluR7于再灌注24h开始增加,72h达到高峰(P<0.05),以后逐渐回落至正常水平。此外,mGluR7阳性细胞还可明显见于梗死区周围,尾壳核,隔外侧核,梨状内核,部分大脑皮质等区域。结论短暂脑缺血能刺激SVZ的mGluR7表达上调,后者可能参与此处由缺血引发的神经前体细胞活化。

Objective Through investigating the expression of metabotropic glutamate receptor 7 subtype （mGluR7） in the subventricular zone in adult rats following focal cerebral ischemia - reperfusion, to explore its role in neurogenesis. Methods The model of acute reperfusion injury after cerebral ischemia in rat was made by middle cerebral artery occlusion （MCAO）. All animals were allowed 2 h ischemia and sacrificed after different durations of reperfusion （6 h, 24 h, 72 h, 7 d, 14 d, 28 d）. The expression of mGluR7 was detected with an immunohistoehemical approach. Results Compared with the control group, the number of mGluR7 immunoreactive cells in the subventricular zone at 24 h after reperfusion in the ischemic side started to increase significantly and peaked at 3 d. However, at 28 d after reperfusion, the number of mGluR7 labeled cells decreased to basal level. In addition, the mGluR7 labeled cells were also detected in dorsal caudate putamen, lateral septal necleus, piriform endonucleus and some areas of cerebral cortex. Conclusion The study implies cerebral ischemia could upregulate the expression of mGluR7 and induce the proliferation of nervous stem cells in the subventricle zone following ischemia.