[Effect of electroacupuncture on hippocampal apoptosis and JNK signal pathway in chronic stress depression rats].

OBJECTIVE

To observe the effect of electroacupuncture (EA) on hippocampal apoptosis and c-Jun N-terminal kinase (JNK) signal pathway in chronic stress depression rats so as to study its mechanism underlying acupuncture-induced improvement of depression.

METHODS

Sixty-five SD rats were randomly divided into control, control + EA, model, EA and Prozac groups, with 13 rats in each. Open-field test was used to detect the rats' behavior changes. The apoptotic rate of the hippocampal cells was detected by Annexin V fluorescein isothiocyanate (FITC)/ Propidium iodide (PI) (Annexin V-FITC/PI) double-staining, and the expression of hippocampal JNK protein detected by Western blot.

RESULTS

After repeated stress stimulation (21 days), the crossing numbers (1.8 +/- 0.2) and rearing times (0.5 +/- 0.01) in the model group were apparently lower than those (48.1 +/- 18.3, 14.2 +/- 2.4) in the control group and those (47.2 +/- 15.8, 13.5 +/- 2.6) in the control + EA group (P < 0.05). Compared with the model group, the crossing numbers and rearing times (40.2 +/- 10.1, 10.3 +/- 2.2) during 3 min in the EA group and those (39.8 +/- 12.4, 10.6 +/- 3.2) in the Prozac group were increased considerably (P < 0.05). The hippocampal apoptotic rate was significantly higher in the model group (67 +/- 10) than in the control (53 +/- 13) and control + EA groups (52 +/- 10, P < 0.05). In comparison with the model group, the apoptotic rate (29 +/- 9) of the EA group and that (51 +/- 13) of the Prozac group were significantly lower (P < 0.05). Compared with the control group, the phosphorylated JNK (p-JNK) level was considerably higher in the model group (P < 0.05); while compared with the model group, the p-JNK level was significantly lower in the EA and Pozac groups (P < 0.05). No apparent differences were found between the EA and and Prozac groups in the aforementioned indexes (P > 0.05).

CONCLUSION

EA can reduce hippocampal apoptotic rate and down-regulate hippocampal p-JNK level in depression rats, which is responsible for its effect in improving depression-induced decreased movement.