title: Adolescent nicotine exposure fails to impact cocaine reward, aversion and self-administration in adult male rats.
abstract: The present experiments examined the effects of adolescent nicotine pre-exposure on the rewarding and aversive effects of cocaine and on cocaine self-administration in adult male rats. In Experiment 1, adolescent Sprague-Dawley rats (postnatal days 28-43) were given once daily injections of nicotine (0.6mg/kg) or vehicle and then tested for the aversive and rewarding effects of cocaine in a combined conditioned taste avoidance (CTA)/conditioned place preference (CPP) procedure in adulthood. In Experiment 2, adolescent Sprague-Dawley rats were pre-exposed to nicotine then tested for cocaine self-administration (0.25 or 0.75mg/kg), progressive ratio (PR) responding, extinction and cue-induced reinstatement in adulthood. In Experiment 1, rats showed significant dose-dependent cocaine-induced taste avoidance with cocaine-injected subjects consuming less saccharin over trials, but no effect of nicotine pre-exposure. For place preferences, cocaine induced significant place preferences with cocaine injected subjects spending significantly more time on the cocaine-paired side, but again there was no effect of nicotine history. All rats in Experiment 2 showed clear, dose-dependent responding during cocaine acquisition, PR testing, extinction and reinstatement with no effect of nicotine pre-exposure. These studies demonstrate that adolescent nicotine pre-exposure does not have an impact on cocaine's affective properties or its self-administration at least with the specific parametric conditions under which these effects were tested.
authors.affiliation: Psychopharmacology Laboratory, Department of Psychology, American University, Washington, DC 20016, United States. Electronic address: rlpomfrey@gmail.com.
authors.forename: Rebecca L
authors.initials: RL
authors.lastname: Pomfrey
authors.affiliation: Psychopharmacology Laboratory, Department of Psychology, American University, Washington, DC 20016, United States.
authors.forename: Tamaara A
authors.initials: TA
authors.lastname: Bostwick
authors.affiliation: Psychopharmacology Laboratory, Department of Psychology, American University, Washington, DC 20016, United States.
authors.forename: B Bradley
authors.initials: BB
authors.lastname: Wetzell
authors.affiliation: Psychopharmacology Laboratory, Department of Psychology, American University, Washington, DC 20016, United States.
authors.forename: Anthony L
authors.initials: AL
authors.lastname: Riley
mesh_terms: D000367:Age Factors; D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects* / Q000502:physiology; D003042:Cocaine / Q000008:administration & dosage*; D004305:Dose-Response Relationship, Drug; D008297:Male; D009538:Nicotine / Q000008:administration & dosage*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012201:Reward; D012646:Self Administration
chemical_list: D009538:Nicotine; D003042:Cocaine
keywords: Adolescent drug exposure; Cocaine self-administration; Conditioned place preference; Conditioned taste avoidance; Nicotine pre-exposure; Sprague–Dawley rats