[Effect of electroacupuncture intervention at different time-points in a day on expression of c-fos and neuronal nitric oxide synthase in medial prefrontal cortex in ketamine addiction rats].

UNLABELLED: To observe the effects of electroacupuncture(EA) stimulation of "Zusanli"(ST 36) and "Sanyinjiao"(SP 6) at different time-points of a day on the expression of c-fos and neuronal nitric oxide synthase (nNOS) in the medial prefrontal cortex (mPFC) in rats with ketamine addiction.

METHODS

A total of 56 SD rats were randomized into control group, saline group, model group and EA group. The EA group was further divided into Zi-shi (23 : 00), Mao-shi (05 : 00), Wu-shi (11 : 00) and You-shi (17 : 00) subgroups (n = 8 in each group or subgroup). Ketamine addiction model was established by intraperitoneal administration of ketamine (100 mg/kg), once a day for 7 days. EA (2 Hz, 3 V) was applied to unilateral "Zusanli" (ST 36) and "Sanyinjiao" (SP 6) acupoints for 30 min, once daily for 7 days. The expression of c-fos and nNOS in the mPFC was detected by immunohistochemistry.

RESULTS

Following EA intervention for 7 days, the animals' daily life activities including body stretching, standing, jumping, circling, falling on the back and fur-licking in the EA group (Wu-shi and You-shi subgroups) were close to those of the normal control and saline groups, being much better than the model group. Compared with the normal control group and saline group, the expression levels of c-fos and nNOS in the mPFC in the model group were significantly upregulated (P < 0.05). Compared with the model group, the expression levels of both c-fos and nNOS were considerably down-regulated in the Wu-shi (11 : 00) and You-shi (17 : 00) subgroups (P < 0.05), rather than in the Zi-shi (23 : 00) and Mao-shi (05 : 00) subgroups (P > 0.05).

CONCLUSION

EA of ST 36 and SP 6 at 11 : 00 and 17 : 00 can decrease the expression o fc-fos and nNOS in the mPFC in ketamine addiction rats, which may contribute to its effects in improving the rats' behavior activity.