Effects Of Exercise On Learning And Memory Of Rats And On The NR1,NR2B And BDNF Gene Expression In Hippocampus

Maintaining brain health and plasticity throughout life is an important public health goal, and it is increasingly clear that exercise can help us to achieve it. Clinical studies have shown that exercise could not only enhance physical health but also enhance mental health, and proper exercise could decrease the risk of cognitive impairment,Alzheimers Disease and dementia. The physical exercise can facilitate the cognitive function and personality, particularly on the advanced function of brain-learning and memory. A number of studies on animals have shown that exercise have benefits for the neuron proliferation,growth and differentiation, facilitate the inducing of LTP, enhance the ability of spatial memory and passive avoidance memory of animals. However the mechanism under this is not clear. NMDA receptor is the very important post-synaptic component , not only involve in the excitement-dependent plasticity, but also play a important role in the communication of neurons. The inducing and maintain of LTP needs the NMDA receptor, and which is seemed to be the key regulator of the synaptic plasticity and the LTP in cortex and hippocampus, forming the important function of CNS and the molecule foundation of learning and memory. BDNF play a wide role in the CNS, more recently, many studies have shown that BNDF is closely implicated in the exercise-induced enhancing of learning and memory. This study has taken NMDAR and BDNF together to discuss function and relation of them in the exercise-induced enhancing of learning and memory.24 select male SD rats are assigned into two groups: control(C, n=8), exercise trained(T, n=16), and the rats of exercise trained group take part in running training for 8 weeks. After 7 weeks training, the rats of the two groups all participate in the learning test of Y maze, and when the 8^th week, the rats of the two groups all participate in the memory test of Y maze. After the last training, T groups are assigned into two groups: T1 group(n=8) and T2 group(n=8). The rats of the T1 group are immediately decollated after the last training, and the rats of T2 group are decollated after 24 hours of the last training. The expression of NRK NR2B and BDNFmRNA are inspected by RT-PCR.The results are as follows:(1) The results of Y maze test have shown that the ability of learning and memory of the rats of T group are better than the rats of C group.(2) Comparing with C group, the 8 weeks training up regulates the expression level of NR1mRNA of the rats of T1 group( 8.5% up regulate), and up regulate the expression level of NR1mRNA of the rats of T2 group significantly (55.1% up regulate, p<0.01); After running training of 8 weeks, the expression level of NR2BmRNA of the rats of T1 group and T2 group all increase significantly(18% and 35.6% up regulate respectively, p<0.01).(3) Comparing with C group, after 8 weeks running training, the expression level of BDNFmRNA increases significantly(69.5% and 24.7% up regulate respectively).Conclusion: 8 weeks running training can facility the spatial learning process of rats , and improve the memory of rats. At the same time, the running training up regulate the expression level of NRK NR2B and BDNF mRNA of hippocampus of rats. The mechanism by which running training enhance learning and memory of rat may have close relation with the increase of the expression level of NR1, NR2B and BDNFmRNA of hippocampus.