Chronic Restraint Stress In Rat Brain Regions Of Bdnf Change And Xiaoyaosan Of Its Regulatory Role

Stress is a series of neuroendocrine responses which is marked with sympathetic nerves exciting and increasing of hypothalamic-pituitary-adrenocortical, resulting functional and metabolic changes,when organisms is exposed to various factors (stress factor) of stimulation. With the high development of Society, work and the pace of life continue to accelerate and the age of mankind demands rising, Mankind will be more in stress , hazards of the stress on the human will continue to deteriorate. The homeostasis is disequilibrium When chronic stress, a series of biochemical changes in the nerve can lead to organic brain damage,and the limbic system related to emotion and memory , especially hippocampal structure is most susceptible to damage. The amygdala is parts of implementation when stress reaction and autonomic nerve and neuroendocrine responses. Many studies have confirmed that the amygdala plays an important role in stress behavioral response.Objective : The topic chooses intercommunication and interaction of the two regions -- the hippocampus and amygdala.it is to discuss distribution and expression of BDNF, observation of brain synaptic plasticity ,regulating role of xiaoyaosan on BDNF when chronic immobilization stress ,from the theory of modern stress, combined with research results in the stress theory . It is further explore human injury and the internal mechanism for the disease when chronic stress, and liver controlling dispersion has the leading position,and part Mechanism that xiaoyaosan eliminate or reduce the chronic stress .This is not only conducive to the basic theories and clinical research of Chinese medicine and development, but it has great significance for prevention and treatment of many stress disease.Methods :1 theoretical study :The following contents were mainly studied in these parts①the basic concept and significance of Syndromes;②relationship among syndrome, disease, pathogenesis and sign;③deficiencies of Syndromes theory;④relation between stress reaction and syndrome;⑤modele of animals syndrome;⑥characteristics of stagnation of liver-QI;⑦pharmaceutical and Syndromes on xiaoyaosan.2 Experimental study: 72 male rats(SD) were randomly divided into six groups and 6 rats in each group:the normal control group of 7 days, the normal control group of 21days, model group of 7 days, model group of 21 days, the group treating with xiaoyaosan of 7 days and the group treating with xiaoyaosan of 21 days (respectively simplified as the 7d xiaoyaopsan group and the 21d xiaoyaosan group.six animals are in a cage,and raising in the house of general level . the indoor temperature is about 22±2°C, relative humidity is about 30-40 percent ,the groups of rats fed conventional feed, free drinking water.Recipes used in the experiment were respectively from Formularies of the Bureau of People's Welfare Pharmacies (xiaoyaosan:Beichaihu 30g, Danggui 30g, Baishao 30g, Baizhu 30g, Fuling 30g, Gancao fried with honey15g, Shengjiang 10g, Bohe 10g).Chinese herbs purchased from Beijing Tongrentang pharmacy, were made into powder by certain procedures for usages by China-Japan Friendship Hospital,it would prepare a certain concentration using distilled water. Rats model of chronic immobilization stress was made by binding rats on the specific bound frame three hours a day for 3 weeks (1week in group A,C,E). xiaoyaosan were injected into the stomach of rats in the groups E and F, the dosage are 5.82g per kg, the cubage is 10ml per kg,The same cubage of distilled water was used for rats in the other group. Killing the rats of group A,C,E and get tissues after 1 week, we deal with the others 3 weeks later.Combining modern experimental methods (immunohistochemistry, RT--PCR, Western blot),from the gene and protein level,it will detect expression of BDNF, analyze internal mechanism of chronic stress on synaptic plasticity and role of xiaoyaosan.Immunohistochemistry findings:In all seven days model rat,BDNF immunoreaction products drop in all regions of hippocampus, in the CA1 and CA3 regions (p<0.05), there is no statistical significance in DG. 21-day model rat is also decline ,in CA1, CA3 (p<0.01), there is no statistical significance in DG. immunoreaction products in the treatment rat increase(p<0.01. p<0.05); in the amygdala , In seven days model rat,BDNF immunoreaction products drop compared to the normal seven days rat', but without statistical significance. 7-day xiaoyaosan rat integral optical density decrease compared to 7- day modle rat'and 7-day normal control rat'(p<0.05); immunoreaction products is drop in 21-day modle rat compared with 21-day normal control rat, but without statistical significance ; immunoreaction products is drop in 21-day xiaoyaosan compared with the 21-day model rat , but without statistical significance. immunoreaction products is drop in 21-day xiaoyaosan compared with the 21-day normal control rat (p<0.05).Western blot results:In all seven days model rat,BDNF immunoreaction products drop in all region of hippocampus, in the DG regions (p<0.01),21-day modle rat immunoreaction products decrease more than 7-day modle rat (CA1, p <0.05 , DG ,p <0.01), there is no statistical significance in CA3. 21-day modle rat immunoreaction products increase after using xiaoyaosan;in the amygdala, modle rat immunoreaction products are not only reduce, but has an increasing trend.its content decrease after using xiaoyaosan,it may be relevant to the amygdala function.RT-PCR results : In CA1 and CA3, DG regions, 7-day model rat BDNF mRNA expression is downward compared with the normal control rat , but no statistical significance, 7-day xiaoyaosan rat is upward compared with 7-day model rat, only in CA1 (P <0.01).21-day model rat compared with 21-day normal rat (P<0.01, P<0.05) ,21-day xiaoyaosan rat compared with 21-day model rat (P<0.01, P<0.05) ,but no difference DG regions;in the amygdala, the expression of BDNF is different with each region of hippocampuin,Almost all increasing after chronic stress, 7-day model rat BDNF mRNA expression is upward compared with 7-day normal control rat, but without statistical significance. 21-day model rat BDNF mRNA expression is upward compared with 21-day normal control rat, but without statistical significance. 7-day model rat BDNF mRNA expression is significantly increase compared with 7-day xiaoyaosan rat (P<0.05) ,21-day xiaoyaosan rat BDNF mRNA expression is significantly reduce compared with 21-day model rat (P <0.01).Conclusion : Chronic restraint stress has effect on expression of BDNF in the hippocampus and amygdala, model rat'BDNF content is downward in the hippocampus, BDNF content increased after using xiaoyaosan; in the amygdala, there is a completely different situation, in conditions of chronic restraint stress, the expression of BDNF is upward .hippocampus and amygdala results are contrary, it may be caused by different control mechanism. This also explains that BDNF protection to nervous system is diminishing, the longer the stress time, This protective effect is weaker, at different stress times, the changes of BDNF is different,it indicate that the loss of BDNF protection during stress is one of the key mechanism stress the protection of the central nervous system damage.After using xiaoyaosan , it changes to the original direction, which might be related to the maintenance of the balance of the body. It illustrate Xiaoyaosan has a significantly's regulatory role hippocampus and amygdala. Butxiaoyaosan's regulatory role is not consistent. This shows the regulatory role of xiaoyaosan has a regional and timing ,same with previous experimental findings. Also shows Xiaoyaosan can affect the nervous system on BDNF protein of synaptic plasticity function, to play a antidepressant role.