The Influences Of Motions Under Different Loads On Aged Rats’ Learning And Memory Capability And Rats’ Hippocampai Nerve Bcl-2、Bax、BNDF

It is complicated biological process in brain to undergo a series of changes onhistomorphology and neurological biochemistry from young to old. Under thebackground of aging society, one of the most problem of brain aging is regression ofcognitive function, whose progressive risk is senile dementia. Hippocampal nerve isthe target organ of executing cognitive function, and also the control center ofcognition, learning and memory of human body. Along with the aging of human body,the hippocampus change accordingly with the aging of brain. It is one of the currentmainstream studies of preventing and treating cognitive regression by exerciseintervention to delay the cognitive aging of hippocampal nerve.This research takes male wistar rats which are16months old as the object. Thosewistar rats are randomly divided into the groups below when formal experimentsare carried out: control group, high-load group(exercising60min perday), moderate-load group(exercising30min per day) and low-load group(exercising15min per day). We adapt the intervention method of8week’s swimming andtake ethological tests after this experiment making use of eight-arm radial maze task.Subsequently, all the rats are dissected in order to evaluate the relative indexes. Weobserve the impact of movements under different loads on the abilities of aged rats’spacial learning and memory capability. Afterwards, we test the influence of motionsunder different loads on the rate of apoptosis of the hippocampal cells and thechanging features of controlling genes as Bcl-2, Bax, as well as BDNF of agedrats. Data from those experiments is analyzed by SPSS13.0.The experiment results show that, contrast the low-load group with the controlgroup, the time aged rats used in the eight-arm radial maze task has significantdifference(P<0.05); the high-load group used more time in the eight-arm radialmaze task than the control group, but there is no statistical difference (P>0.05). Inthe contrast of the numbers of memory that aged rats appeared when learning and memorizing, the low-load exercise group and the control group has significantstatistical differences(P<0.05); the high-load group compared with the controlgroup also has statistical difference (P<0.05); there is no statistical difference betweenthe moderate-load group and the control group (P>0.05). In the contrast of the Bcl-2expression of aged rats’ hippocampal neurons, there is a highly significantdifference (P<0.01) between the low-load group and the control group; there is alsohighly significant difference (P<0.01) between the high-load group and the controlgroup. In the contrast of the Bax expression of aged rats’ hippocampalneurons, there is significant difference between the low-load group and the controlgroup (P<0.05); there is no statistical difference between the moderate-load groupand the control group (P>0.05); and there is highly significant difference betweenthe high-load group and the control group (P<0.01). In the contrast of the BDNFexpression of aged rats’ hippocampal neurons, there is no statisticaldifference between the low-load group and the control group (P>0.05); here issignificant difference between the moderate-load group and the controlgroup (P<0.05); and there is highly significant difference between the high-loadgroup and the control group (P<0.01).The results also show that different exercise load on the aged rats effectsdifferently on their learning and memory capability. Particularly, low-load sportstraining can effectively improve the learning and memory capability of aged rats,while high-load exercise training shows negative effect on their ability of learning andmemory. Hippocampal neural nerve Bcl-2and Bax of the aged rat reacts differentlyto different exercise load. Specifically, appropriate exercise load can effectivelyinhibit the apoptosis of nerve cells in the hippocampus, while long-term and high-loadexercise will significantly increase the apoptosis phenomenon. Besides, the geneticexpression of BDNF in hippocampal neural will increase to high level with theincrease of exercise load. In the proper range of exercise load, BDNF improves theability of learning and memory in aged rats. However, long-term and high-loadexercise probably increase the possibility of BDNF lesion which will decrease thelearning and memory ability of aging rats.