Effects Of Different Load Swimming On Memory Extraction And Expression Of OXA, OX1R And NCAM In Hippocampus Of Rats

Objective:Through the different load intensity exercise intervention in rats,we observed the effects of exercise on memory retrieval ability and detected the rat hippocampal proteins expression of OXA 、 OX1 R and NCAM, providing experimental data to reveal the possible mechanisms of memory retrieval ability influenced by different load exercise.Methods: Selected 40 2-month-old male Sprague-Dawley rats and randomly divided into three groups:Control Group(C,n=10), Medium Load group(M,n=13), Excess load Group(O,n=17). After 8 days Morris water maze(7 days place navigation experiment and 1 day space exploration experiment),group C feeding 8 weeks naturally,group M do swimming exercise intervention for 8 weeks, group O do over load swimming exercise intervention for 8 weeks.Through 1 day space exploration experiment to evaluate the effects of different load exercise on memory retrieval ability.Put rats to death according to the building time,detect the expression of hippocampal proteins in rats.Detected blood testosterone content by ELISA technique;Detected the m RNA expression level by Real time PCR;Detected the protein expression level by Western blot;Scanning immunofluorescence slice to observe the distribution of OXA in hippocampal,and analysis the expression of OXA by intensity. Results:(1)Body weight monitoring results: since the end of third week average weight of M and O group were lower than that of C group(P<0.01),since the end of fifth week the weight of O group was lower than M group(P<0.05).(2)Results of Morris water maze: During the navigation experiment,compare 3 to 7 days with two days ago, average escape latency of each group rats become shorter(P<0.05,P<0.01),and the trends beginning stabilized from the third day.During the space exploration, the number through the platform of each group after the exercise intervention were less than before(P<0.05,P<0.01).After the exercise intervention, the number through the platform of M group were more than C group(P<0.05),and O group were less than M and C group(P<0.05).(3)Results of blood testosterone:Blood testosterone levels in group M and O were lower than in group C(P<0.01),and blood testosterone levels in group O were lower than in group M(P<0.01).(4) Results of hippocampal related protein m RNA test: The expression of NCAM m RNA and OXA m RNA of group M were higher than group C(P<0.05),the expression of OX1 R m RNA of group M was lower than group C(P<0.05); the expression of OXA m RNA of group O was lower than group C(P<0.05).(5)Results of hippocampal related protein test:The expression of NCAM of group M were higher than group C and group O(P<0.05), the expression of OX1 R of group M were lower than group C and group O(P<0.05).(6)Results of immunofluorescence test:The immunofluorescence intensity of OXA in hippocampal(CA3、CA1、DG) of group M were lower than group C(P<0.05).(7)Results of every index’s correlation test:The expression of OXA had significantly positive correlation with the expression of OX1 Rm RNA and OX1 R in hippocampal(P<0.05).The expression of NCAM had significantly negative correlation with OX1 Rm RNA and OXA in hippocampal(P<0.01). The expression of NCAM m RNA had significantly negative correlation with OX1 R m RNA in hippocampal(P<0.01).Conclusion:(1)Medium load exercise had improved the space memory retrieval ability of rats,increased the expression of NCAM,decreased the expression of OXA and OX1 R,the mechanism may relate to the increasing expression of NCAM in hippocampal affected by OX1 R signal.(2)Over load exercise had damaged the space memory retrieval ability of rats,but had no effect on the expression of OX1R、OXA and NCAM.