Electroacupuncture alleviated the depression-like behavior by regulating FGF2 and astrocytes in the hippocampus of rats with chronic unpredictable mild stress

Studies have shown that basic fibroblast growth factor (FGF2) is a neurotrophic factor associated with depression. Electroacupuncture (EA) has been shown to be an effective treatment for depression. In the current study, we observed the effects of EA on hippocampal FGF2 and astrocytes, and further investigated the mechanism underlying antidepressant effect of EA. The chronic unpredictable mild stress (CUMS) method were selected to induce depressive-like behaviors of rats. Paroxetine is a commonly used antidepressant and was used as a positive control drug in this experiment. The male adult Sprague Hawley (SD) rats were randomized to four experimental groups (normal control group, CUMS group, EA group and paroxetine group, n = 10/group). EA intervention was administered once daily for 14 days at acupuncture points Baihui (GV20) and Yintang (GV29). Rats in the paroxetine group received daily paroxetine administered intragastrical. Behavioral test, immunohistochemistry (IHC), western blot (WB) and quantitative real-time PCR (qPCR) were conducted to evaluate the intervene effect and the changes of FGF2 and astrocyte marker (glial fibrillary acidic protein, GFAP). The results showed that EA and paroxetine could improve depression-like behavior in CUMS rats, and up-regulated the expression level of FGF2 in the hippocampus, increased GFAP protein expression and the mean optical density of GFAP-immunoreactive astrocyte (GFAP-ir astrocyte). Our findings have identified that EA could ameliorate depressive-like behaviors possibly by regulating the expression of FGF2 in the hippocampus, and the mechanism might be related to the effect of FGF2 on astrocytes.