成年大鼠局灶性脑梗死后齿状回神经元前体细胞的发生研究

目的初步探讨脑缺血后神经元前体细胞的发生机制。方法建立一侧大脑中动脉缺血再灌注模型,应用神经元前体细胞的标志物DCX(Doub lecortin)检测缺血再灌注后不同时相点海马齿状回神经元前体细胞的增殖情况。结果再灌注后第7天梗死侧及非梗死侧齿状回DCX阳性细胞数达到最高峰,与相应假手术组比较,差异有统计学意义(P<0.05);同时各个时相点梗死侧与非梗死侧比较,差异均有统计学意义(P<0.05);再灌注后第21天双侧齿状回DCX阳性细胞数基本恢复至正常水平。结论局灶性脑缺血可以诱导成年大鼠神经元前体细胞的发生,这对于脑缺血后的神经修复可能起关键性作用;其机制可能是缺血区域产生的一些神经发生调节因子弥散到神经发生区域所致。

Transient focal cerebral ischemia-induced neurogenesis in dentate gyrus of adult rats

Objective To study the neurogenesis after focal cerebral ischemia in the dentate gyrus of adult rats and the mechanisms responsible for stroke-induced neurogenesis.Methods Animal models of middle cerebral artery occlusion(MCAO) were established in 16 adult rats,and four of another 8 rats served as normal control and four underwent sham operation.Doublecortin was used to label neuron precursors.The proliferation rate of neuron precursors in the dentate gyrus on day 1,7,14,21 after reperfusion was examined.Results The doublecortin-positive cells in the ipsilateral dentate gyrus and contralateral dentate gyrus reached the highest level on day 7 after reperfusion,up to 2.4-fold higher than that of sham-operated rats(P<0.05),then down near to the normal level on day 21 after reperfusion.There was a significant increase of doublecortin-positive cells in ipsilateral dentate gyrus on each time point as compared with contralateral dentate gyrus (P<0.05).Conclusion Neurogenesis in the dentate gyrus of the adult rat brain can be initiated after focal cerebral ischemia,which may be crucial in brain repair after ischemia.