Glia atrophy in the hippocampus of chronic unpredictable stress-induced depression model rats is reversed by electroacupuncture treatment.

Background: Growing evidence indicates that glia atrophy contributes to the pathophysiology and possibly the pathogenesis of major depressive disorder. Electroacupuncture (EA), one of Chinese traditional therapy, has potent antidepressant-like effect in many clinical studies. The mechanism by which EA improves behavioral deficits is still unclear.
Method: Chronic unpredictable stress (CUS)-induced depression model rats were used to study the effect of EA treatment. EA was performed on acupoints 'Bai-Hui' (Du 20) and unilateral 'An-Mian' (EX 17) once daily for three consecutive weeks, two weeks post CUS procedure. The antidepressant-like effect of EA treatment was analyzed by physical state (PS) and open field test (OFT). Astrocytic marker glial fibrillary acidic protein (GFAP) level in the hippocampus was detected by immunohistochemistry, Western blot analysis and reverse transcription-polymerase chain reaction (RT-PCR).
Results: Exposure to CUS resulted in a decrease of behavioral activity, whereas a daily session of EA treatment significantly reversed the behavioral deficit of these depression model rats. Moreover, the levels of GFAP mRNA and protein were decreased in the hippocampus of depression model rats. Intriguingly, EA treatment blocked effectively the decreased GFAP level.
Limitation: The relative small number of the depression model rats may cause some bias of behavioral tests.
Conclusion: EA has potential antidepressant-like effect on CUS-induced depression model rats, which might be mediated by affecting the glial atrophy in the hippocampus.
(© 2010 Elsevier B.V. All rights reserved.)