The novel mGluR2/3 agonist LY379268 attenuates cue-induced reinstatement of heroin seeking

In humans, drug-associated stimuli can provoke heroin relapse during abstinence. In rats, cues paired with heroin self-administration reinstate heroin seeking in a relapse model. The neurobiological mechanisms involved in this reinstatement, however, are largely unknown. Here, we determined the effect of LY379268, an mGluR(2/3) agonist that decreases evoked glutamate release, on cue-induced reinstatement of heroin seeking. Systemic injections of LY379268 attenuated reinstatement of heroin seeking induced by exposure to a discrete tone-light cue that was previously paired with heroin infusions during self-administration training. In contrast, LY379268 had no effect on heroin self-administration. Results indicate that glutamate plays an important role in cue-induced reinstatement of heroin seeking and suggest that mGluR(2/3) agonists should be considered for the treatment of opiate relapse. (c) 2005 Lippincott Williams & Wilkins.