[Gene chips-aided analysis on the profiles of hippocampal whole-genome expression in depression rats following electroacupuncture treatment].

Objective: To observe the effect of electroacupuncture (EA) on the profiles of hippocampal whole-genome expression in depression rats so as to study its underlying mechanism in relieving depression.

Methods: Thirty male SD rats were randomized into normal, model and EA groups (n = 10/group). Depression model was established by chronic unpredictable stress stimulation (forced ice-water swimming, electric shock, tail-clamping, etc.) and lonely raising for 21 days. EA (2 Hz, 1 mA) was applied to "Baihui"(GV 20) and "Yintang" (EX-HN 3) for 15 min, once daily for 7 days. The rats' ethological activities (horizontal and vertical movements) were detected with Open-field test in Morris labyrinth, and 1% sucrose solution consumption was detected. After termination of the treatment, the rats were killed and their hippocampal tissues were taken out for analyzing the whole-genome expression with Roche-NimbleGen chips (Rattus norvegicus 12 x 135 Karray).

Results: Compared with normal group, the distance of horizontal movement, rearing times, and sucrose consumption at day 21 and day 28 of model group decreased considerably (P < 0.01). In comparison with model group, the sucrose consumption at day 28 in EA group increased significantly (P < 0.05). Results of gene expression microarray displayed that compared with normal group, of the down-regulated and up-regulated genes due to modeling, 101 and 125 turned to normal in their expression, respectively following EA treatment. The down-regulated genes involve energy and substance metabolism, protein biosynthesis, etc., and the up-regulated genes involve blood clotting, immunity, inflammation, apoptosis, etc.

Conclusion: EA of GV 20 and EX-HN 3 can normalize chronic stress stimulation induced down- and up-regulated expression of many genes in depression rats, which may contribute to its clinical effect in relieving depression.