局灶性脑缺血大鼠皮质和尾壳核神经干细胞增殖分化与nNOS的表达

本研究旨在探讨局灶性脑缺血再灌注大鼠皮质和尾壳核神经干细胞的增殖分化与nNOS表达的关系。大脑中动脉线栓法制作大鼠局灶性脑缺血再灌注模型,5溴脱氧尿核苷(BrdU)标记分裂增殖细胞,免疫组化单标和双标记技术检测各组大鼠缺血侧皮质和尾壳核BrdU阳性细胞和nNOS的表达。模型组大鼠皮质和尾壳核BrdU阳性细胞再灌注后3d开始增多,14d达高峰,nNOS阳性细胞再灌注后7d表达增强,28d达高峰,BrdU/nNOS双标细胞在14d达高峰,占皮质BrdU阳性细胞数的42.95%,尾壳核内占42.56%。新生细胞分化组BrdU阳性细胞和BrdU/nNOS双标细胞显著多于模型组(P<0.05),皮质双标细胞占BrdU阳性细胞数的54.08%,尾壳核内占47.84%。提示局灶性脑缺血可增强大鼠皮质和尾壳核的增殖能力,部分增殖细胞分化为nNOS阳性神经元,参与神经网络的重建。

THE RELATIONSHIP BETWEEN THE PROLIFERATION AND DIFFERENTIATION OF NEURAL STEM CELLS AND THE EXPRESSION OF nNOS POSITIVE CELLS IN THE CORTEX AND CAUDOPUTAMEN OF ADULT RATS AFTER FOCAL CEREBRAL ISCHEMIA

The aim of this study is to explore the relationship between the proliferation and differentiation of neural stem cells and the expression of nNOS positive cells in the cortex and caudoputamen of adult rats after focal cerebral ischemia.In middle cerebral artery occlusion (MCAO) models, bromodeoxyuridine (BrdU) was injected to label proliferative cells. Then BrdU positive cells and nNOS positive cells in the cortex and caudoputamen were observed with immunohistochemistry.In the group of MCAO rats, BrdU positive cells in the cortex and caudoputamen obviously increased at 3 d after reperfusion, and arrived at the peak at 14 d after reperfusion. nNOS expression in the cortex and caudoputamen also increased 7 d after reperfusion and arrived at the peak at 28 d after reperfusion. BrdU/nNOS double positive cells increased and arrived at the peak at 14 d after reperfusion. The percentage of BrdU/nNOS double positive cells to BrdU positive cells is 42.95% in cortex and 42.56% in caudoputamen. In the group of cellular rebirth and differentiation, BrdU positive cells and BrdU/nNOS double positive cells are more than those in the group of models (P<0.05). The percent age of BrdU/nNOS double positive cells to BrdU positive cells is 54.08% in cortex and 47.84% in caudoputamen. Our study suggests that the proliferation of cells in the cortex and caudoputamen can be improved after focal cerebral ischemia. Some of them differentiate into nNOS positive neurons and take part in the reconstruction of neural network after focal cerebral ischemia.