Abstract
BACKGROUND: This study aimed to investigate the effect of electroacupuncture (EA) on behavior in a rat model of chronic unpredictable mild stress (CUMS) and to explore the underlying molecular mechanisms. METHODS: A total of 45 adult male Sprague-Dawley rats were randomly divided into three groups: the control, CUMS, and CUMS plus EA groups. Rats in the CUMS and EA groups were subjected to a 3-week CUMS condition, while rats in the EA group received EA at the Baihui (GV 20) acupoint (2 Hz, 0.6 mA) for 10 min once daily before being subjected to the CUMS condition. The sucrose preference test (SPT) was used as a measure to infer activation of the pleasure response to depression-like behaviour. After the behavioral test, 5-bromodeoxyuridine (BrdU) was intraperitoneally injected (100 mg/kg) and brain samples were collected 24 h later for the detection of hippocampal BrdU. Cell proliferation was determined according to the proportion of BrdU-positive cells. Brain-derived neurotrophic factor (BDNF) expression was detected. RESULTS: The severity of anhedonia, BDNF(+) cells, and BrdU(+) neurons in DG significantly decreased in CUMS rats, and was accompanied by a reduced BDNF and BrdU(+) expression (P<0.05). After EA, the low levels of BDNF(+) cells and BrdU(+) expression and the depression-like behavior increased markedly (P<0.05). CONCLUSIONS: EA contributes to neuroprotection against CUMS by enhancing BDNF expression and improving hippocampal neurogenesis.