The Effect Of Different Load Exercise On Learning Of Rats And The Expression Of Orexin A?OX1R And NCAM In The Cerebellum

Objective: We intervene rats by the long-term different load exercise to investigate the effect of different load exercise on learning ability of rats and the expression of Orexin A ? OX1 R and NCAM in rat's cerebellum, providing nerve biological datas for brain health and long-term exercise on different learning mechanisms.Methods: There are 30 two-month-old male SD rats randomly divided into 3 groups, including the control group(DWMC, n = 10), the moderate load group(DWMM, n = 10) and the overload exercise group(DWMO, n = 10). The rats of group DWMC were naturally fed for 8 week. There were 8-week-swimming for the rats of group DWMM. The rats of group DWMO swam 8 weeks. After this, each group was conducted with the Morris water maze test, including 7 days of navigation test and 1-day space exploration experiments.And then,we obtained the cerebellum tissues.The serum testosterone levels of rats was measured with Enzyme-linked immunosorbent assay(ELISA) in each group;The expression of OX1 RmRNA OrexinAmRNA, NCAMmRNA in rat's cerebellum were measured with real-time quantitative PCR assay(Real-time qPCR); The protein expression of OX1R?NCAM in rat's cerebellum were measured with Western blot assay(Western blot); Confocal immunofluorescence microscopy were performed to observe the distribution of OrexinA in the cerebellum and to analyze the intensity of OrexinA.Results: 1.Weight test results: From the 1st week to the 3rd week in this experiment, the body weight of rats in the control group(DWMC) ? long-term moderate load group(DWMM) and long-term overload exercise group(DWMO) was no significant change. Since the 3rd week, rat's body weight in group DWMM and group DWMO was significantly lower than group DWMC(P <0.01); On the 4th week, the body weight of group DWMO was significantly lower than group DWMM(P <0.05); In the 6th week, the body weight of group DWMO remained significantly lower than group DWMM(P <0.01).2.Morris water maze test results: navigation test was designed for7 days.On 7 days,group DWMM was easier to find the platform than group DWMC.Particularly on the1 st day, the average escape latency time of group DWMM was significantly lower than group DWMC(P <0.01), whereas there was no significant difference between the group DWMC and group DWMO. From the 4th day to the 7th day, the 3 groupsof rats were involved in the plateau. The space exploration experiment was designed for 1 day, after rats were immersed into water from the second quadrant of the Morris water maze, the average number of traversing the platform of group DWMM was significantly more enormous than group DWMC(P <0.05), while the average number of times of group DWMO was significantly lower than group DWMC and group DWMM(P <0.05, P <0.01). 3.Serum testosterone test results: There was no significant difference between the group DWMC and group DWMM in the level of serum testosterone(P> 0.05); The serum testosterone level of group DWMO were significantly lower than group DWMC and group DWMM(P <0.01). 4.Real-time PCR results: The expression of NCAM mRNA and OrexinA mRNA in group DWMM was significantly higher than group DWMC(P <0.05);The expression of OX1 R mRNA in group DWMM was significantly lower than group DWMC(P <0.01); The expression of NCAM mRNA and OrexinA mRNA in group DWMO was significantly lower than group DWMM(P<0.05, p<0.01); The expression of NCAM mRNA ?OrexinA mRNA and OX1 R mRNA in group DWMO was significantly lower than group DWMC(P <0.01).5.Western blot test results: The protein expression of NCAM in group DWMM was significantly higher than group DWMC(P <0.05);The protein expression of OX1 R in group DWMM was significantly lower than group DWMC(P<0.05); The protein expression of NCAM in the cerebellum of group DWMO was significantly lower than group DWMM(P <0.05). 6.Immunofluorescence assay results: The protein of Orexin A in the cerebellum mainly located in the cell cytoplasm,it was surrounded by the nucleus periphery.The average optical density of Orexin A in group DWMM was significantly higher than group DWMC(P <0.05),The average optical density of Orexin A in group DWMM was significantly higher than group DWMO(P <0.05).7.The results of the Correlation analysis: There is a significant positive correlation between the expression of protein NCAM ? NCAM mRNA and the average optical density of Orexin A in the cerebellum(P <0.01);There is a significant positive correlation between the expression of Orexin A mRNA ?NCAM mRNA and the average optical density of Orexin A in the cerebellum(P <0.01,P <0.05); There is a significant positive correlation between the expression of OX1 RmRNA and protein OX1R(P <0.01);There is a significant positive correlation between the expression of NCAM mRNA and the average immunofluorescence density of expression of Orexin A(P<0.05).Conclusion:1.The moderate load exercise increases the expression of NCAMmRNA?protein NCAM and OrexinAmRNA in thecerebellum, increasing the ability of learning.The mechanism may be involved in the upregulation NCAM and the add of OX1 R signal.2.Overload exercise reduces the expression of Orexin A mRNA in rat's cerebellum.However, there was no significant decrease between NCAM m RNA ? protein NCAM and the ability of spatial learning,suggesting that NCAM may be involved in the repair of nerve damage.