Abstract: Objective To explore the biological mechanisms of electroacupuncture (EA) for depression. Methods Forty male adult Sprague-Dawley rats were randomly divided into control group (n=8), model group (n=8), EA group (n=8) and fluoxetine group (n=8). Depressive models were established with lonely raising and chronic unpredictable mild stress. They were tested with Open-field Test, and the expression of phosphodiesterase 4 (PDE4)A and PDE4D in hippocampus was detected with RT-PCR. Results The cross and rear scores were significantly lower in the model group than in the control group (P<0.001), while it increased in the EA group and the fluoxetine group (P<0.001). Compared with the model group, the expression of PDE4A and PDE4D decreased in the EA group (P<0.001). Conclusion Electroacupuncture may relieve depression through inhibiting the expression of PDE4A and PDE4D.

Key words: depression, electroacupuncture, chronic stress, phosphodiesterase 4, rats