The Effects Of Sports Fatigue On The Ultrastructure Of Neurons In The Motor Region Of Cerebral Cortex And Its Mechanism

Experimental objective: To study the effect of sports fatigue on the synaptic ultrastructure of neurons in the main motor region of rat cerebral cortex by establishing exercise fatigue model and training the rats with increasing load to exhaustion.Experiment methods: In this study,20 healthy male Wistar adult rats were selected,weighing 170-200 g,purchased from SCXK(Gan)2018-0002,production license of experimental animal center of Lanzhou University School of Medicine,feeding in cages,feeding according to national standard rodent feed,free diet,drinking water,natural light,indoor temperature 22°C-23°C,humidity 20%-40%,and the ultraviolet lamp of lab for regular sterilization,once every two days in bedding,once every two days as large rat weight.After adaptive feeding for 3 days,20 rats were randomly divided into 2groups,10 rats in the control group were in group C,and 10 rats in the exhaustion group were in group F.All rats were FGB immediately after exercise.The gene expression of PI3k/Akt/Gsk-3β/Tau in brain tissues was determined by qRT-PCR.The ultrastructural changes in the cerebral cortical motor areas of rats(10 in the control group and 10 in the fatigue group)were measured by ultrathin sections and observed by transmission electron microscopy.Experiment results:(1)Indexes to judge the sports fatigue of rats: from the behavioral point of view,the running posture of rats in the running platform changes from the pedaling type to the ambush type,and the rats can't keep running after staying at the end of the runway and being driven by electric stimulation or stick;compared with the control group,the body weight of rats after exercise fatigue is reduced;the serum of rats is tested,the FGB concentration is reduced immediately after exercise fatigue.(2)Compared with the control group,the area of cell body and nucleus of neurons decreased,the density of synapses decreased,the curvature of synaptic interface increased,the number of synaptic vesicles in presynaptic membrane increased,the length and width of synaptic space became longer and narrower,and the thickness,length and area of PSD increased.(3)Compared with the control group,the gene expression of PI3 K and Akt decreased,and that of GSK-3β and tau increased significantly.Experiment conclusion:(1)Through the comprehensive judgment of behavioral and physiological indexes,the animal experimental model of exercise fatigue established in this experiment is successful.(2)The cell and nuclear area of neurons decreased significantly immediately after exercise fatigue;the density of synapses decreased significantly;the curvature of neuronal contact interface increased;the number of synaptic vesicles in the presynaptic membrane of neurons increased significantly;the width of synaptic space of neurons decreased significantly;and the thickness,length and area of PSD increased significantly.indicating that the synaptic interface structure of neurons in the main motor area of cerebral cortex changes significantly immediately after exercise fatigue.(3)The gene expression of PI3 K and Akt decreased significantly immediately after exercise fatigue,and the gene expression of GSK-3β and Tau increased significantly;these changes may be the molecular signaling basis that triggered the above ultrastructural changes.