acupuncture at ht7 suppresses morphine selfadministration at high dose through gaba system in the previous study acupuncture at ht7 has shown to attenuate the selfadministration of morphine at a low dose 01mgkg in this study it was further investigated whether acupuncture at ht7 could attenuate the morphine selfadministration at a high dose 05mgkg male spraguedawley rats weighing 270300g were used after surgery of catheterization animals were trained to selfadminister morphine solution 05mgkg using daily 1h session under fixed ratio 1 schedule for 3 weeks animals that had shown stable morphinetaking establish baseline variation less than 20 of the mean of three consecutive days were subjected to the acupuncture treatment bicuculline and sch 50911 were used to investigate the possible relation between the effect of acupuncture and the gaba receptor system acupuncture at ht7 but not at control acupoint li5 suppressed spontaneous morphinetaking behavior significantly in addition the effect of acupuncture was blocked by both gaba receptor antagonists the results of this study suggest that acupuncture at ht7 suppresses morphinetaking behavior through the mediation of gaba receptor system