title: Combined effects of buprenorphine and a nondrug alternative reinforcer on i.v. cocaine self-administration in rats maintained under FR schedules.
abstract: Although previous studies have shown that pharmacological agents, such as buprenorphine, and alternative nondrug reinforcers, such as money or sweetened solutions, reduce cocaine self-administration, few studies have examined the combined effects of these two approaches. The purpose of the present study was to evaluate the effects of the opioid partial against buprenorphine (0.1 mg/kg) and concurrent access to either water or a glucose plus saccharin solution (G+S, 3% and 0.125% wt/vol) in rats self-administering intravenous (IV) cocaine (0.4 mg/kg per infusion) under fixed-ratio schedules (FR2, 8 or 32). One group had concurrent access to water and another group had concurrent access to G+S. After 3 consecutive days of stable cocaine self-administration, a single buprenorphine injection (0.1 mg/kg IV) was administered 30 min before the start of the experimental session for 3 consecutive days. To summarize the results, (1) the presence of an alternative non-drug reinforcer significantly reduced cocaine self-administration, (2) buprenorphine selectively decreased cocaine, but not water or G+S, self-administration; (3) the decrease in cocaine infusions by buprenorphine was greatest on the first day of buprenorphine administration; and (4) expressed as a percentage of baseline conditions, the combination of buprenorphine and G+S produced a greater decrease in cocaine self-administration than either buprenorphine or G+S alone. These results indicate that combined treatment with buprenorphine and concurrent access to a sweetened solution is a more effective strategy for reducing cocaine self-administration than either strategy alone.
authors.affiliation: Department of Psychiatry, University of Minnesota Medical School, Minneapolis 55455, USA.
authors.forename: S D
authors.initials: SD
authors.lastname: Comer
authors.forename: S T
authors.initials: ST
authors.lastname: Lac
authors.forename: C L
authors.initials: CL
authors.lastname: Wyvell
authors.forename: M E
authors.initials: ME
authors.lastname: Carroll
mesh_terms: D000818:Animals; D002047:Buprenorphine / Q000494:pharmacology*; D003042:Cocaine / Q000494:pharmacology*; D003216:Conditioning, Operant / Q000187:drug effects*; D005247:Feeding Behavior / Q000187:drug effects / Q000523:psychology*; D007275:Injections, Intravenous; D008297:Male; D009292:Narcotic Antagonists / Q000494:pharmacology*; D009294:Narcotics / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D012646:Self Administration / Q000523:psychology
chemical_list: D009292:Narcotic Antagonists; D009294:Narcotics; D002047:Buprenorphine; D003042:Cocaine