title: Role of nicotinic acetylcholine receptors in the effects of cocaine-paired contextual stimuli on impulsive decision making in rats.
abstract: BACKGROUND
  Chronic cocaine exposure produces unconditioned enhancement in impulsive decision making; however, little is known about the effects of cocaine-paired conditioned stimuli on this behavior. Thus, this study explored the effects of cocaine-paired contextual stimuli on impulsive decision making and the contribution of nicotinic acetylcholine receptors (nAChRs) to this phenomenon.
  
  
  METHODS
  Rats were trained to achieve stable performance on a delay discounting task, which involved lever press-based choice between a single food pellet (small reward) available immediately and three food pellets (large reward) available after a 10-, 20-, 40-, or 60-s time delay. Rats then received Pavlovian context-cocaine (15 mg/kg, i.p.) and context-saline (1 ml/kg, i.p.) pairings in two other, distinct contexts. Subsequently, delay discounting task performance was assessed in the previously cocaine-paired or saline-paired context following pretreatment with saline or cocaine (15 mg/kg, Experiment 1) or with saline or the nAChR antagonist, mecamylamine (0.2 and 2 mg/kg, Experiment 2), using counterbalanced within-subjects testing designs.
  
  
  RESULTS
  Independent of cocaine pretreatment, rats exhibited greater decrease in preference for the large reward as a function of delay duration in the cocaine-paired context, relative to the saline-paired context. Furthermore, systemic mecamylamine pretreatment dose-dependently attenuated the decrease in preference for the large reward in the cocaine-paired context, but not in the saline-paired context, as compared to saline.
  
  
  CONCLUSIONS
  Cocaine-paired contextual stimuli evoke a state of impulsive decision making, which requires nAChR stimulation. Drug context-induced impulsivity likely increases the propensity for drug relapse in cocaine users, making the nAChR an interesting target for drug relapse prevention.
authors.affiliation: Department of Psychology, University of North Carolina, CB# 3270, Davie Hall, Chapel Hill, NC, USA.
authors.forename: Xiaohu
authors.initials: X
authors.lastname: Xie
authors.forename: Amy A
authors.initials: AA
authors.lastname: Arguello
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Reittinger
authors.forename: Audrey M
authors.initials: AM
authors.lastname: Wells
authors.forename: Rita A
authors.initials: RA
authors.lastname: Fuchs
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D002755:Choice Behavior / Q000187:drug effects; D003042:Cocaine / Q000008:administration & dosage* / Q000494:pharmacology; D019970:Cocaine-Related Disorders / Q000378:metabolism / Q000523:psychology; D003216:Conditioning, Operant / Q000187:drug effects*; D003657:Decision Making / Q000502:physiology*; D007175:Impulsive Behavior / Q000378:metabolism / Q000523:psychology*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D011978:Receptors, Nicotinic / Q000378:metabolism / Q000502:physiology*; D012055:Reinforcement Schedule; D012201:Reward
chemical_list: D011978:Receptors, Nicotinic; D003042:Cocaine