The Effect Of Swimming Exercise On The 5-HT And PKA-CREB-BDNF Signaling Pathways In The Prefrontal Cortex Of Aggressive Behavior Rats

Research Objectives:Aggressive behavior is the main reason for human violent crime,the violent behavior such as fighting and abuse others have caught the attention of the society from all walks of life even in the campus.If this behavior is not improved,it will give caused great harm to the physical and mental health of teenagers.The occurrence of violent aggressive behavior is affected by environmental,psychological and social factors,but the nerve circuits of aggressive behavior is similar to the control of emotional loop.The studies confirms that the abnormal structure or function of brain such as prefrontal cortex,amygdala and hippocampus are related to the aggressive behavior,and the neurotransmitters such as 5-HT and DA are also linked to the aggressive behavior.The studies found that the brain of BDNF and its receptor TrkB by stimulating various signaling pathways play a role to protect the brain health.Physical exercise is not only an effective measure and auxiliary treatment of diseases such as cardiovascular and obesity,but also beneficial to brain health.The studies have found that exercise can effectively reduce the negative emotions such as depression,anxiety and anger,and improve the mood.The aggression is one of the negative emotions.The studies have confirmed that exercise can alleviate the aggressive behavior of rats.Therefore,this thesis will discuss if the exercise relieves the aggressive behavior of the rats because of 5-TH and BDNF which is improved through PKA-CREB-BDNF signaling pathway.The biological mechanism of exercise to the aggressive behavior was discussed and supplemented.To provide a more adequate theoretical basis to reduce the frequency of aggressive behavior.Research methods:1.Experimental animal and model:The experimental animals used 3 months of 50 healthy male SD rats and weighing about 200g in the laboratory for adaptive breeding a week.Then using the resident-intruder method to establish the aggressive model and randomly divided into:A is control group:living in group and do not make any processing;B is model group:living in single cage and 3 weeks invasion;C is model exercise group:living in single cage and 3 weeks invasion,6 weeks swimming training;D is exercise group:living in group and 6 weeks swimming training:E is invasion group:living in group and invasion of single cage rats.2.Experimental methods:The use of aggressive behavior test,open field test and Morris water maze test of each groups rats to determine the behavioral indicators,and then taken the biochemical indicators.Using Elisa to test the frontal lobe tissue and blood 5-HT contents,and test PKA,CREB,BDNF and its receptor TrkB protein expression in prefrontal cortex of rats were detected by Western blot.Research result:1.The test results of bodyweight:The bodyweight of rats in the establishment of the resident-intruder aggressive model and 6 weeks of swimming exercise showed a different degrees of growth.2.The test results of aggressive behavior:There were no significant differences in the latency and the number of attacks between the two groups after modeling.After 6 weeks of exercise,the latency of the model group was significantly higher than that of the model exercise group(P<0.01),the number of attacks in rats showed a significantly decreased(P<0.05).3.The test results of open field test:There were no significant differences in the total distance,standing times and the number of modifications in each groups after a week of adaptation.The rats of each groups were compared with the control group,only the two modeling groups were significantly decreased in the total distance,standing times and the number of modifications after 3 weeks of modeling(P<0.05).The total distance of the model exercise respectively compared with the model group and exercise group were showing significantly decreased(P<0.05),the number of modifications of the model exercise group respectively compared with the model group and exercise group were showing significantly increased after 6 weeks of exercise(P<0.05).4.The test results of Morris water maze test:After the end of modeling,the latency of the rats in the exercise group was significantly decreased than the model group on the fourth day of the place navigation(P<0.05),and the three indexes of the spatial probe experiment were no significant differences.After 6 weeks of exercise,the latency of rats in the second,third and fourth day of exercise group were significantly shorter than the model group(P<0.05),and in the fourth day of the model exercise group was significantly decreased than that of the model group in the place navigation(P<0.05);the number of rats crossing the platform and the third quadrant activity time of the exercise group were significantly higher than the model group in the spatial probe experiment(P<0.05).5.The test results of Elisa:The 5-HT level in the prefrontal cortex and blood of model group were significantly lower than that in the control group(P<0.05).The 5-HT level in the prefrontal cortex and blood of the exercise group were significantly higher than that in the model group(P<0.05).The 5-HT level in blood of the model exercise group was significantly higher than that in the model group(P<0.05).6.The test results of Western blot:Compared with the control group,the expressions of PKA and TrkB protein in the prefrontal cortex of the model group were significantly decreased(P<0.05),and the expressions of CREB and BDNF protein in the prefrontal cortex of the model group were very significantly decreased(P<0.01),and the expressions of CREB and BDNF protein in the prefrontal cortex of the model exercise group were significantly decreased(P<0.05),and the expressions of BDNF andTrkB protein in the prefrontal cortex of the exercise group showed a very significantly increased(P<0.01).Then compared with the model group,the expressions of PKA and CREB protein in the prefrontal cortex of the model exercise group showed a significantly increased(P<0.05),and the expressions of CREB,BDNF and TrkB protein in the prefrontal cortex of the exercise group were very significantly increased(P<0.01),and the expression of PKA protein in the prefrontal cortex of the exercise group showed a significantly increased(P<0.05).The expressions of CREB and BDNF protein in the prefrontal cortex of the model exercise group were very significantly decreased compared with the exercise group(P<0.01).7.The correlation analysis result of 5-HT content,PKA,CREB,BDNF protein expressions in the prefrontal cortex of rats:The content of 5-HT in the prefrontal cortex of rats was positively correlated with the expression of PKA protein at 0.05 level.The content of 5-HT in the prefrontal cortex and the expression of BDNF,PKA and CREB,CREB and BDNF were significantly positive correlations at 0.01 level.Research conclusion:1.The rats in resident-intruder model were reduced in the exploration of the external environment and the ability of spatial learning and memory was weakened.But the behavior and the learning and memory of rats in modeling groups were improved after 6 weeks of swimming training.2.The 5-HT levels in the prefrontal cortex and the blood of rats were increased after 6 weeks of swimming training so that the rat aggressive behavior is alleviated.3.The 6 weeks swimming training may increased the expression of BDNF protein to alleviate the aggressive behavior,and the relevant mechanism may be:5-HT and its receptors through the PKA-CREB-BDNF mediated pathway to enhance the expression of BDNF,and BDNF play a protective and promote the function of nerve activity to alleviate the aggressive behavior.