Effects Of Aerobic Treadmill Exercise On The Expression Of BDNF,TrkB And CREB In Hippocampus And Learning And Memory

Objective: To explore the effect of long-term and regular aerobic exercise on the learning and memory ability of hippocampus,the expression of BrainDerived Neurotrophic Factor,Tropomyosin-Related Kinase B,Cyclic AMP Response Element Binding Protein in hippocampus and the effect of aerobic exercise serum on HT-22,so as to provide theoretical basis for the improvement of brain cognition and learning and memory by aerobic exercise.Methods:Aerobic exercise,water maze and sampling in rats.23 SPF male SD rats of two months old were randomly divided into two groups after 8 days of adaptive exercise: The Aerobic Axercise Group(Group E,n = 11)was given 6-week incremental load aerobic exercise with 6 days of incremental aerobic exercise per week.The initial speed of the running platform is 15 m/min,which increases to 18 m/min after 5 min,20 m/min after 10 min,and the gradient of the running platform is 0° in the first two weeks.The running platform gradient is increased to 5° when the speed reaches 20 m/min at the beginning of the third week,and the training platform gradient is increased to 50,60,60 and 65 min,respectively.The Control Group(Group C,n = 12)was fed regularly without exercise.All the rats were performed in morris water maze test in the 7th week.The rats were killed within 24 hours after the end of the space exploration experiment.The brain was cut off and the hippocampus was taken out.BDNF,TrkB and CREB contents in the hippocampus were measured.The experiment of cell culture in serum of rats.In hippocampus HT-22 cell,fetal bovine serum was replaced by rat serum of 10% E Group and rat serum of 10% C Group respectively,and cells were treated with complete medium for 72 h.BDNF,TrkB and CREB protein contents in cell extracts and cell culture supernatant of E Group and C Group were measured by ELISA.The experimental results of each test method were expressed as M±SD.Independent sample T test was used for statistical analysis,p<0.05 was the standard of significant difference between groups.Results: The content of hemoglobin and the ratio of heart to body weight were significantly increased by increasing load aerobic exercise;Although it can not significantly improve the escape latency of water maze test navigation experiment,it can significantly increase the number of crossing platform in space exploration experiment of rats;It can significantly up regulate the expression of BDNF in the hippocampus of rats.The increase of BDNF content will promote the combination of BDNF with TrkB and the significant increase of TrkB expression,activate the downstream signal pathway,and realize the significant increase of CREB expression in the hippocampus,at the same time,the expression of BDNF and TrkB in serum of group E was significantly increased,but there was no significant difference in the expression of CREB;The expression of BDNF and TrkB in HT-22 cells cultured in serum of group E and group C was significantly higher than that of group C,but there was no significant difference in CREB expression;The expression of BDNF and CREB in cell culture supernatant of group E was higher than that of group C,and that of TrkB was lower than that of group C,but there was no significant difference.Conclusion: Six weeks' incremental load aerobic exercise can make the body of rats produce benign changes,the expression of BDNF,TrkB,CREB in hippocampus increased,and the spatial learning and memory ability of rats improved;the changes of BDNF,TrkB expression in hippocampus caused by aerobic exercise serum may be one of the molecular mechanisms of aerobic exercise to improve brain cognition and learning memory.