title: Competition between the conditioned rewarding effects of cocaine and novelty.
abstract: Access to novelty might provide an alternative learning history that competes with conditioned drug reward. We tested this suggestion in rats using a place conditioning procedure with cocaine and novelty. In Experiment 1, rats were conditioned with cocaine to prefer one side of an apparatus. In a subsequent phase, cocaine exposure continued; however, on the unpaired side, separate group of rats had access to novel objects, cocaine injections, or saline with no objects. Pairings with novel objects or cocaine shifted a preference away from the cocaine-paired environment during drug-free and drug-challenge tests. Experiment 2 tested novelty's impact when cocaine exposure was discontinued. The identical procedures were used except drug exposure ceased on the cocaine-paired side during the second phase. Both groups expressed a preference for the cocaine compartment. This preference was maintained for rats that did not have novel objects; however, rats that experienced novelty spent similar amounts of time in both compartments during both tests. Overall, the conditioned rewarding effects of novelty competed with those of cocaine as evidenced by a change in choice behaviors motivated by drug reward.
authors.affiliation: Department of Psychology, University of Nebraska-Lincoln 68588-0308, USA.
authors.forename: Carmela M
authors.initials: CM
authors.lastname: Reichel
authors.forename: Rick A
authors.initials: RA
authors.lastname: Bevins
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D003042:Cocaine / Q000008:administration & dosage*; D003216:Conditioning, Operant / Q000187:drug effects* / Q000502:physiology*; D018765:Dopamine Uptake Inhibitors / Q000008:administration & dosage*; D005106:Exploratory Behavior / Q000502:physiology*; D008297:Male; D009043:Motor Activity / Q000187:drug effects / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012201:Reward
chemical_list: D018765:Dopamine Uptake Inhibitors; D003042:Cocaine