成年和老年大鼠局灶性脑缺血后脑室下区细胞的增殖分化

Proliferation and differentiation of neural stem cells in subventricular zone in adult and aged rats after focal cerebral ischemia

目的:比较老年和成年大鼠局灶性脑缺血后脑室下区(SVZ)神经干细胞的增殖与分化。方法:制作大脑中动脉梗死模型, 用免疫组化法检测SVZ的5-溴脱氧尿核苷(BrdU)、神经元核抗原(NeuN)及胶质纤维酸性蛋白(GFAP)阳性细胞数的变化。结果:SVZ的BrdU阳性细胞在正常组和假手术组成年大鼠明显多于老年大鼠。实验组成年和老年大鼠均在缺血后增加,28 d时仍高于正常水平,但成年大鼠各时间点均明显高于老年大鼠。在新生细胞中部分细胞是BrdU/NeuN或BrdU/GFAP双标细胞, 但老年大鼠BrdU/NeuN双标细胞明显少于成年大鼠。结论:大鼠脑缺血激活SVZ神经干细胞增殖能力,成年大鼠明显强于老年大鼠,且新生细胞分化为神经元的比例也明显高于老年大鼠。

To investigate the difference of the proliferation and differentiation of neural stem cells in the subventricular zone （SVZ） between adult and aged rats after focal cerebral ischemia. Methods： Rats were subjected to transient middle cerebral artery occlusion （MCAO）. Imrnunohistochemical single and double staining with antibodies against BrdU, NeuN and GFAP were used to determine proliferation and differentiation of SVZ. Results： In non-ischemia rats, BrdU positive cells in SVZ of adult rats were much more than those of aged rats. After MCAO, BrdU positive cells in SVZ of rats were obviously increased, and BrdU positive cells in SVZ of adult rats were more than those of old rats all the time. BrdU/GFAP double positive ceils of aged rats were much more than those of adult rats, but BrdU/NeuN double positive cells of aged rats were less than those of adult rats. Conclusion： Neural stem cells in SVZ are activated after cerebral ischemia. Proliferation and differentiation of neural stem cells in SVZ of adult rats are stronger than that of old rats.