植物雌激素对去卵巢大鼠海马NOS阳性神经元及学习记忆的影响

目的 :观察植物雌激素对去卵巢大鼠海马NOS阳性神经元及学习、记忆的影响 ,对中枢神经系统的保护作用。方法 :采用NADPH d酶组化观测各组大鼠海马各功能亚区NOS阳性神经元数目和Morris水迷宫行为学方法。结果 :定位航行实验显示各组大鼠的平均逃避潜伏期无明显差异 ,而空间探索实验显示植物雌激素组平台象限的游泳距离百分比和穿台次数均高于去卵巢对照组。在海马CA1和齿状回 (DG) ,植物雌激素组NOS阳性神经元数目较去卵巢对照组明显增多 (P <0 .0 5 )。结论 :植物雌激素能增加海马神经元NOS的表达 ,改善去卵巢大鼠的学习记忆能力 ,提示对中枢神经系统退行性病变具有保护作用。

Effects of phytoestrogens on NOS positive neurons in hippocampus and on cognitive functions of ovariectomized rats

Objective: To investigate the effects of phytoestrogens on the NOS positive neurons in the hippocampus and on the cognitive function of the ovariectomized rats,providing information for the protecting mechanism of phytoestrogens on the central nervous system. Methods: NADPH-d histochemical staining and Morris water maze test were used to observe the number of NOS positive neurons in the hippocampus and the ability of learning and memory. Results: The result of place navigation showed that the average escape latency were not significantly different among the 4 groups (P>0.05), but the result of spatial probe test showed that the percentage of the total swim distance within the platform quadrant and the total number of crossing the platform of the phytoestrogen group were significantly higher than those of the ovariectomized control group (P<0.05). Compared with estrogen group and sham-operated group, the results of spatial probe test of the phytoestrogen group showed no significant difference (P>0.05) in the Morris water maze test; In the CA1 subregion and dentate gyrus of the hippocampus, the number of NOS positive neurons increased significantly in the phytoestrogen group (P<0.05)and no significant difference was observed among the phytoestrogen group, estrogen group and sham-operated group (P>0.05). Conclusion: The present study suggests that phytoestrogen can obviously increase the expression of NOS in the hippocampus, and improve the ability of learning and memory to some extent, playing a role in protecting neurodegeneration disease of the central nerve system.