Influence of electroacupuncture of "Baihui" (GV 20) and "Sanyinjiao" (SP 6) on hippocampal 5-HT and AChE immuno-activity in chronic depression rats

Objective: To investigate the influence of electroacupuncture (EA) on 5-serotonin (5-HT) and acetyl cholinesterase (AChE) activities in hippocampus tissue in chronic stressed-induced depression rats.

Methods: Thirty-two Wistar rats were randomized into normal control group (n=10), model group (n=11) and EA group (n=11). Chronic depression model was established by lonely raising, and chronic unpredictable mild stress for 21 days. EA (2 Hz, 1 mA) was applied to "Baihui" (GV 20) and "Sanyinjiao" (SP 6) for 20 minutes, once daily for 14 days. 5-HT and AChE expression of hippocampal CA 4 region was detected by using immunohistochemistry, and their integrated optical density (IOD) values were determined by using image analysis system.

Results: Compared with normal control group, IOD values of 5-HT and AChE immuno-reaction (IR) positive neurons in hippocampal CA 4 region of model group decreased significantly (P<0.05). In comparison with model group, the IOD values of 5-HT and AChE IR positive neurons of CA 4 region in EA group increased significantly (P<0.05). No significant differences were found between EA and normal control groups in IOD values of both 5-HT and AChE IR positive neurons.

Conclusions: EA can upregulate 5-HT and AChE expression in hippocampal CA 4 region in depression rats, which may contribute to its effect in relieving depression.