Exercise training increase BDNF/TrkB mRNA, prevents memory loss and ameliorate the hippocampal morphology in multiple sclerosis model

Abstract

Purpose: We aimed to verify the implications of four weeks of consistent exercise on the mRNA of the brain-derived (BDNF) and the tropomyosin-related kinase B (TrkB) receptor that may contribute to ameliorates the hippocampal morphology and induced enhancement of memory in experimental autoimmune encephalomyelitis (EAE) after the diseases recovery stage. Methods: Female Lewis rats were randomly separated into three groups, control group (Co), EAE without exercise (EAE), EAE with exercise (EAE+Ex) , each group contains (10 rats) . All rats underwent to the Morris water maze (MWM) test for four days in week and prop test was done in fifth day and repeated in day 30 post induction. Exercise was prescribed by motorized treadmill starting at 17 m/min and gradually increased, a total duration of 30 minutes per day, five days a week and discontinued two weeks after the induction. EAE was induced subcutaneously after two weeks of exercise as rats injected with an inoculum containing 50 ug guinea pig spinal cord homogenate emulsified in incomplete Freund’s adjuvant and 2mg of heat-mycobacterium at the tail base. Results: EAE+Ex significantly increases the BDNF mRNA (P< 0.05) and TrkB (P> 0.02) mRNA levels compared to the EAE groups. The Co group increased significantly more than the EAE group (P< 0.01). Swimming speed performance was faster in EAE+Ex (P< 0.02) compared to EAE group lead to improved hippocampus function. Conclusion: It seems that the provision of four weeks of exercise training is capable of increasing the mRNA of BDNF and its receptor along with ameliorating the hippocampus morphological which can have positive effects on memory impairment during EAE disease.