title: Effects of continuous nicotine treatment and subsequent termination on cocaine versus food choice in male rhesus monkeys.
abstract: One complicating factor in cocaine addiction may be concurrent exposure and potential dependence on nicotine. The aim of the present study was to determine the effects of continuous nicotine treatment and subsequent termination on cocaine versus food choice in rhesus monkeys (Macaca mulatta). For comparison, we also determined effects of the nicotinic receptor antagonist mecamylamine on cocaine versus food choice during continuous saline and nicotine treatment. Rhesus monkeys (N = 3) responded under a concurrent schedule of food pellet (1 g) and intravenous cocaine (0-0.1 mg/kg/injection) availability. Saline and ascending nicotine doses (0.1-1.0 mg/kg/hr, intravenous) were continuously infused for 7-day treatment periods and separated by 24-hr saline treatment periods. Acute effects of mecamylamine (0.32-1.8 mg/kg, intramuscular, 15 min pretreatment) were determined during continuous saline and 0.32-mg/kg/hr nicotine treatments. During saline treatment, cocaine maintained a dose-dependent increase in cocaine choice. Nicotine treatment did not alter cocaine versus food choice. In contrast, preference of 0.032 mg/kg/injection cocaine was attenuated 24 hr following termination of 0.32-mg/kg/hr nicotine treatment, despite no somatic abstinence signs being observed. Acute mecamylamine enhanced cocaine choice during saline treatment and mainly suppressed rates of behavior during nicotine treatment. Overall, continuous nicotine exposure, up to 1 mg/kg/hr, does not enhance cocaine choice and does not produce nicotine dependence, as demonstrated by the lack of abstinence signs.
authors.affiliation: School of Pharmacy, Virginia Commonwealth University.
authors.forename: Kathryn L
authors.initials: KL
authors.lastname: Schwienteck
authors.affiliation: Department of Pharmacology and Toxicology and Institute for Drug and Alcohol Studies, Virginia Commonwealth University.
authors.forename: S Stevens
authors.initials: SS
authors.lastname: Negus
authors.affiliation: Department of Pharmacology and Toxicology, Virginia Commonwealth University.
authors.forename: Justin L
authors.initials: JL
authors.lastname: Poklis
authors.affiliation: Department of Pharmacology and Toxicology and Institute for Drug and Alcohol Studies, Virginia Commonwealth University.
authors.forename: Matthew L
authors.identifier: 0000-0003-4949-5246
authors.initials: ML
authors.lastname: Banks
mesh_terms: D000818:Animals; D002755:Choice Behavior / Q000187:drug effects*; D003042:Cocaine / Q000008:administration & dosage*; D004305:Dose-Response Relationship, Drug; D005502:Food; D008253:Macaca mulatta; D008297:Male; D008464:Mecamylamine / Q000008:administration & dosage / Q000494:pharmacology; D009538:Nicotine / Q000008:administration & dosage* / Q000494:pharmacology; D018733:Nicotinic Antagonists / Q000008:administration & dosage / Q000494:pharmacology; D012646:Self Administration
chemical_list: D018733:Nicotinic Antagonists; D008464:Mecamylamine; D009538:Nicotine; D003042:Cocaine