Apelin-13 Improves The Novel Object Recognition Memory Impaired By Forcing Swimmingg Strss In Rats

Prior researches of the lab show that apelin-13 plays antidepressant effect in a variety of depression model. On this basis, we further study the effects of apelin-13 on the novel object recognition(NOR) memory of rats. This experiment firstly studied the forced swimming stress(FSS) model that could damage the NOR memory in the rat, and then the improvement effect of apelin-13 on the NOR memory of rats were studied in the damage model of FSS, finally the experiment further studied the mechanism of improvement effect of apelin-13 on the NOR memory injured by FSS. The experimental results are as follows. Discrimination indexes of One FSS and Two FSS groups were significantly decreased compared with control group, suggesting that FSS impaired NOR memory of rats. Compared with saline group, the discrimination index of apelin-13(1μg) group and apelin-13(2μg) group had no significant difference, suggesting that apelin-13 had no effect on NOR memory of rats. The discrimination index of Saline group was significantly decreased compared with control group, and the discrimination index of apelin-13 group was significantly increased compared with saline group, suggesting that FSS impaired NOR memory of rats and apelin-13 improved the damage effect. In addition, the immobility time of apelin-13 was significantly decreased compared with the saline group on day 2, suggesting that apelin-13 had antidepressant effect. Compared with saline group, the discrimination index of apelin-13 group increased significantly, and the discrimination index of PD+apelin-13 group decreased significantly compared with apelin-13 group, suggesting that apelin-13 improved NOR memory of rats impaired by FSS and PD98059 blocked this effect of apelin-13. Compared with saline group, the discrimination index of apelin-13 group increased significantly, and the discrimination index of LY+apelin-13 group decreased significantly compared with apelin-13 group, suggesting that apelin-13 improved NOR memory of rats impaired by FSS and LY294002 blocked this effect of apelin-13. The results suggest that apelin-13 improves novel object recognition memory injured by forced swimming stress through ERK1/2 and PI3 K signaling pathway in rats.