Effects Of Ovariectomizy And Polygala Tenuigenin On Learning And Memory

In order to study the change on the ability of learning and memoryin the ovariectomized mice and the effect of polygala tenuigenin on themaintenance of memory, the ability of learning and memory of theanimal are investigated by the behavior study and pathological method.the results showed as follow:â‘ after ovariectomized for two months, the animals' responseslowed down in step-through test and the STL was shortened. Afterovariectomized for three months and four months, the animals'correct-response rate depressed in the radial-arm maze.â‘¡Serum SOD, MDA and hippocampus AchE were examined.The ovariectomized animals had a lower serum SOD level, higherserum MDA level and higher hippocampus AchE level than normalanimals.â‘¢The number of NOS positive neurons of ovariectomizedanimals was decreased in the subregions of hippocampus compared towhich of the control group.â‘£The maintenance of memory of ovariectomized mice could besignificantly improved by the polygala tenuigenin. The number of NOSpositive neurons also significantly increased in CA1 and DG, butdecreased in CA3.⑤Polygala tenuigenin with doses of 25, 12.5, 6.25μg.ml^-1 couldincreased the viability of PC12 cells injuried by H₂O₂.In conclusion, the memory improvement of Polygala tenuigeninon the ovariectomized mice may be responsible for its estrogen-likeaction; Polygala tenuigenin could protects cell from H₂O₂-inducedinjury.