title: Naltrexone attenuates cue- but not drug-induced methamphetamine seeking: a possible mechanism for the dissociation of primary and secondary reward.
abstract: The present study was aimed to clarify the role of the opioid system in the reinstatement of methamphetamine (METH)-seeking behavior in METH self-administering rats. Following 12 days of self-administration of METH, the replacement of METH with saline resulted in a gradual decrease in lever press responses (extinction). Under extinction conditions, METH-priming or re-exposure to cues previously paired with METH infusion markedly increased the responses (reinstatement of drug-seeking). Naltrexone administered 30 min before re-exposure to METH-associated cues attenuated reinstatement of drug-seeking behavior. On the other hand, administration of this antagonist had no effect on the reinstatement induced by METH-priming. We discussed these findings in relation with the dissociation of primary and secondary reward, suggesting that an opioid mechanism is responsible for this dissociation. Further, these results indicate the possibility of using naltrexone as an anti-relapse agent.
authors.affiliation: Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
authors.forename: Kusnandar
authors.initials: K
authors.lastname: Anggadiredja
authors.forename: Katsuya
authors.initials: K
authors.lastname: Sakimura
authors.forename: Takato
authors.initials: T
authors.lastname: Hiranita
authors.forename: Tsuneyuki
authors.initials: T
authors.lastname: Yamamoto
mesh_terms: D000818:Animals; D016739:Behavior, Addictive / Q000503:physiopathology; D000697:Central Nervous System Stimulants / Q000008:administration & dosage*; D003216:Conditioning, Operant / Q000187:drug effects; D008297:Male; D008694:Methamphetamine / Q000008:administration & dosage*; D009271:Naltrexone / Q000494:pharmacology*; D009292:Narcotic Antagonists / Q000494:pharmacology*; D051381:Rats; D012201:Reward; D012646:Self Administration
chemical_list: D000697:Central Nervous System Stimulants; D009292:Narcotic Antagonists; D008694:Methamphetamine; D009271:Naltrexone