Electroacupuncture Of The Molecular Mechanisms Of Neural Plasticity In Rats In Chronic Stress Model Of Depression

Deression is a very serious psychosis disorder nowadays. Acupuncture, one of the major parts of Traditional Chinese Medicine, can alleviate the symptoms of depression patients. Mechanisms of its effect, however, remain unclear. Therefore, our research focused on electroacupuncture (EA) therapy for depression by using depression rat model to explore some possible mechanisms. 1. To compare the theraputic effect of 2Hz and 100Hz EA, We used forced swimming test rat model of depression. We found 2Hz, but not 100Hz EA, can decrease the immobility time greatly compared with 100Hz EA and control. Both of 2Hz and 100Hz have no effect on the rat open-field activity. Therefore, 2Hz has antidepressant effect. 2. On the basis of behavior improvement, we started to study the possible mechanisms of EA therapy on forced swimming test. By using HPLC-ECD technique, we analysed the content of monoamines and their metabolisms in rat striatum. We found that the content of 5-HIAA in 2Hz group decreased greatly compared with 100Hz group. Both of the 2Hz and 100Hz groups can improve DA and 5-HT content in rat striatum, and they do not have much influence on NE and DOPAC. By using immunoassay technique, we analysed the content of β-endorphine in rat hypothalamus and pituitary. We found that both of 2Hz and 100Hz group can improve the content of β-endorphine in rat hypothalamus greatly, however, they do not have much influence on the content of pituitary. 3. 2Hz EA was employed to treat chronic stress rat model of depression, with the result that the sucrose intake was significantly increased in EA group, suggesting an antidepressant effect. The weight and activity of the EA group decreased greatly compared with control, however, it did not have much difference compared with model. 4. We used immunohistochemistry technique to explore the change of BDNF and its receptor TrkB in rat cortex and hypothalamus. We found that there was minute BDNF and TrkB expression in control group, BDNF and TrkB level in model increased greatly compared with control, while BDNF and TrkB level in EA group increased greatly compared with control and model. We used immunohistochemistry technique to explore the change of p-CREB in rat cortex, hypothalamus, hippocampus and amygdala.We found that the level of p-CREB in these brain regions is relative high compared with model, and the p-CREB in rat cortex, hypothalamus, hippocampus in EA group improved greatly compared with model. The p-C4 电针影响慢性应激抑郁模型大鼠神经可塑性的分子机制研究difference compared with model. We used immunohistochemistry technique to explore the change of caspase-3 in rat cortex.We found there is almost no caspase-3 expression in control, and there is much caspase-3 expression in model, there is minute caspase-3 expression in EA group. 5. We used Western blotting method to detect p-CREB expression in rat cortex. As a result, there was minute p-CREB expression in naive group. p-CREB expression level in the model group increased greatly compared with the naive group. While p-CREB expression level in the EA group increased much significantly compared with the control group , as well as the model group. Our research indicated that 2Hz EA can decrease the immobility time in rat forced swimming test, and improve sucrose intake in chronic stress depression model. It can also decrease the content of 5-HIAA in rat striatum. Furthermore, it can increase the BDNF, TrkB and p-CREB level in the cortex, hypothalamus, hippocampus and amygdala of rat. The work suggested that the possible mechanisms of EA therapy includes : promoting BDNF and TrkB, p-CREB expression, decreasing the content of 5-HIAA. The work may have some impact on future research of EA therapy for depression.