Effect of acupuncture on naloxone-precipitated withdrawal syndrome in morphine-experienced rats: The mediation of GABA receptors

Repeated morphine administration increases extracellular dopamine levels in the nucleus accumbens, which results in behavioral sensitization that can be suppressed by acupuncture at Shenmen (HT7) points. The present study was conducted to investigate the effects of acupuncture at HT7 on morphine withdrawal syndrome as well as to explore the role of GABA receptors in mediating the effects of HT7 acupuncture. We induced morphine withdrawal by injecting naloxone to rats that self-administer morphine and evaluated the effects of acupuncture and/or GABA receptor antagonists on their withdrawal symptoms. Acupuncture at HT7, but not at the control point LI5, significantly decreased symptoms of morphine withdrawal. HT7 inhibition of the withdrawal syndrome was blocked by pretreatment with either the GABAA receptor antagonist bicuculline or the GABAB antagonist SCH 50911. These findings suggest that the effects of acupuncture on suppression of morphine withdrawal syndrome are mediated, at least in part, through GABA receptors.

► Chronic morphine causes serious withdrawal syndrome in human and animals.
► We explore the effect of acupuncture on the morphine withdrawal syndrome in rats.
► Acupuncture decreases the withdrawals, which is blocked by GABA receptor antagonists.
► The acupuncture effects of withdrawal are mediated at least via GABA receptors.