title: Nicotine and cocaine self-administration using a multiple schedule of intravenous drug and sucrose reinforcement in rats.
abstract: There appears to be a relatively narrow range of contingencies in which intravenous (i.v) infusions of nicotine will maintain responding in rats. The schedule of reinforcement typically used when investigating i.v. nicotine self-administration is a simple fixed-ratio (FR) schedule. This study determined if responding in rats could be established using a multiple schedule of either i.v. cocaine or nicotine and sucrose reinforcement. Following training of individual components with each reinforcer, rats were placed on an FR15 60-s timeout multiple schedule of cocaine (0.3 mg/kg/infusion) and sucrose (45 mg pellets) reinforcement or an FR5 60-s timeout multiple schedule of nicotine (0.03 mg/kg/infusion) and sucrose (45 mg pellets) reinforcement. Both cocaine and nicotine maintained significant levels of responding under the multiple schedule. Pretreatment with the dopamine D1 antagonist SCH 23390 increased cocaine-maintained responding, but not sucrose responding. Acute pretreatment with the nicotinic antagonist mecamylamine or SCH 23390 specifically decreased nicotine self-administration. Extinction of the individual nicotine and sucrose components resulted in decreases in responding in each component under extinction. These results indicate that i.v. nicotine maintains responding under a multiple schedule. This procedure may be useful when studying the specificity of drug pretreatments on nicotine self-administration.
authors.affiliation: Department of Psychology, Creighton University, Omaha, Nebraska 68178-0321, USA. dustinstairs@creighton.edu
authors.forename: Dustin J
authors.initials: DJ
authors.lastname: Stairs
authors.forename: Nichole M
authors.initials: NM
authors.lastname: Neugebauer
authors.forename: Michael T
authors.initials: MT
authors.lastname: Bardo
mesh_terms: D000779:Anesthetics, Local / Q000008:administration & dosage*; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D001552:Benzazepines / Q000494:pharmacology; D003042:Cocaine / Q000008:administration & dosage*; D003216:Conditioning, Operant / Q000187:drug effects; D018492:Dopamine Antagonists / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D005108:Extinction, Psychological / Q000187:drug effects; D005518:Food Preferences / Q000187:drug effects*; D007262:Infusions, Intravenous / Q000379:methods; D008297:Male; D008464:Mecamylamine / Q000494:pharmacology; D009538:Nicotine / Q000008:administration & dosage*; D018722:Nicotinic Agonists / Q000008:administration & dosage*; D018733:Nicotinic Antagonists / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012054:Reinforcement, Psychology; D012646:Self Administration / Q000379:methods; D013395:Sucrose / Q000008:administration & dosage*
chemical_list: D000779:Anesthetics, Local; D001552:Benzazepines; D018492:Dopamine Antagonists; D018722:Nicotinic Agonists; D018733:Nicotinic Antagonists; C534628:SCH 23390; D013395:Sucrose; D008464:Mecamylamine; D009538:Nicotine; D003042:Cocaine