title: On the persistence of cocaine-induced place preferences and aversions in rats.
abstract: BACKGROUND
  Rats develop preferences for places associated with the immediate rewarding effects of cocaine and aversions for places paired with the drug's delayed negative effects. The motivation to seek cocaine should therefore depend upon the relative magnitude of these two opposing effects of the drug.
  
  
  OBJECTIVE
  The current study tested this notion by assessing the relative persistence of the positive and negative associations formed between environmental cues and the immediate or delayed effects of cocaine.
  
  
  METHODS
  Rats were administered 1.0 mg/kg intravenous cocaine and placed into a distinctive environment either immediately or 15-min after injection, alternating daily with pairings of a second environment with saline. After four drug-place and four saline-place pairings, rats were returned to their home cages for 1, 7, or 21 days after which a 15-min place preference test was conducted. In a second experiment, the effectiveness of a single reconditioning session (one drug-place and one saline-place pairing) to reactivate learned cocaine-place associations was assessed after 1 or 3 weeks of drug abstinence.
  
  
  RESULTS
  Places associated with the immediate effects of cocaine were preferred (CPP), while places associated with the delayed effects of cocaine were avoided (CPA). The persistence of these effects differed with CPP remaining viable at 3 weeks of withdrawal, while CPA was no longer present after 1 week. Reconditioning with an additional cocaine-place pairing failed to reinstate the CPA.
  
  
  CONCLUSIONS
  Cue-induced "relapse" of cocaine-seeking behavior may be fueled in part by an increased persistence of positive relative to negative associations with drug-paired stimuli.
authors.affiliation: Behavioral Pharmacology Laboratory, Department of Psychological and Brain Sciences, University of California, Santa Barbara, CA 93106-9660, USA.
authors.forename: Zu-In
authors.initials: ZI
authors.lastname: Su
authors.forename: Ashley
authors.initials: A
authors.lastname: Santoostaroam
authors.forename: Jennifer
authors.initials: J
authors.lastname: Wenzel
authors.forename: Aaron
authors.initials: A
authors.lastname: Ettenberg
mesh_terms: D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects* / Q000502:physiology; D003042:Cocaine / Q000008:administration & dosage*; D003213:Conditioning, Psychological / Q000187:drug effects* / Q000502:physiology; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D012201:Reward; D013997:Time Factors
chemical_list: D003042:Cocaine