慢性复合应激对大鼠学习和记忆功能及齿状回神经前体细胞增殖的影响

为研究慢性复合应激对成年雄性大鼠学习和记忆功能及齿状回(DG)神经前体细胞增殖的影响,将成年雄性Wistar大鼠随机分为对照组和应激组,应激组动物每天交替暴露于复合应激原中,持续6周。应激结束后,用Morris水迷宫测试大鼠空间学习记忆成绩。同时,采用BrdU标记分裂细胞方法,观察比较各组大鼠DG内BrdU阳性细胞数的变化和差异。结果显示:应激组动物的学习与记忆成绩均优于对照组(P<0.05);与对照组相比,应激组大鼠DG内BrdU阳性细胞数量显著增加(P<0.05)。上述结果表明:慢性复合应激导致大鼠的学习与记忆能力加强,DG内BrdU阳性细胞增多,提示神经细胞数量增加可能是应激所引起的大鼠学习记忆能力增强的原因之一。

EFFECTS OF CHRONIC MULTIPLE STRESS ON THE FUNCTION OF LEARNING AND MEMORY AND THE PROLIFERATION OF THE PRECURSOR CELLS IN DENTATE GYRUS OF RATS

The present study was to investigate the effect of chronic multiple stress on the function of spatial learning and memory and the proliferation of the neuronal precursor cells in the dentate gyrus(DG)in rats. Adult male Wistar rats were randomly divided into two groups: the multiple stressed group and the control group. Rats in the multiple stressed group were irregularly and alternatively exposed to the chronic multiple stress for 6 weeks. After that, all rats were tested for the performance of spatial learning and memory in Morris water maze. By using bromodeoxyuridine (BrdU) labeling method, the number of newly generated cells was determined and the comparison was made between the two groups. The results showed that: (1) The latent period to search platform in Morris water maze of rats in stressed group was significantly longer than that in the control group (P<0.05). (2) The number of BrdU-labeled cells in the DG of multiple stressed rats was higher than that of the control group (P<0.05). The results indicate that the newborn cells in the DG induced by the chronic multiple stress may participate in the process of enhancing the spatial learning and memory function of the rat.