title: Caudal Nucleus Accumbens Core Is Critical in the Regulation of Cue-Elicited Approach-Avoidance Decisions.
abstract: The nucleus accumbens (NAc) is thought to be a site of integration of positively and negatively valenced information and action selection. Functional differentiation in valence processing has previously been found along the rostrocaudal axis of the shell region of the NAc in assessments of unconditioned motivation. Given that the core region of the NAc has been implicated in the elicitation of motivated behavior in response to conditioned cues, we sought to assess the role of caudal, intermediate, and rostral sites within this subregion in cue-elicited approach-avoidance decisions. Rats were trained to associate visuo-tactile cues with appetitive, aversive, and neutral outcomes. Following the successful acquisition of the cue-outcome associations, rats received microinfusions of GABAAand GABABreceptor agonists (muscimol/baclofen) or saline into the caudal, intermediate, or rostral NAc core and were then exposed to a superimposition of appetitively and aversively valenced cues versus neutral cues in a "conflict test," as well as to the appetitive versus neutral cues, and aversive cues versus neutral cues, in separate conditioned preference/avoidance tests. Disruption of activity in the intermediate to caudal parts of the NAc core resulted in a robust avoidance bias in response to motivationally conflicting cues, as well as a potentiated avoidance of aversive cues as compared with control animals, coupled with an attenuated conditioned preference for the appetitive cue. These results suggest that the caudal NAc core may have the capacity to exert bidirectional control over appetitively and aversively motivated responses to valence signals.
authors.affiliation: Department of Psychology (Scarborough), University of Toronto , 1265 Military Trail , Toronto, Ontario M1C 1A4, Canada.
authors.forename: Laurie
authors.initials: L
authors.lastname: Hamel
authors.affiliation: Department of Psychology (Scarborough), University of Toronto , 1265 Military Trail , Toronto, Ontario M1C 1A4, Canada.
authors.forename: Tharshika
authors.initials: T
authors.lastname: Thangarasa
authors.affiliation: Department of Psychology (Scarborough), University of Toronto , 1265 Military Trail , Toronto, Ontario M1C 1A4, Canada.
authors.forename: Osai
authors.initials: O
authors.lastname: Samadi
authors.affiliation: Department of Psychology (Scarborough), University of Toronto, 1265 Military Trail, Toronto, Ontario M1C 1A4, Canada; Department of Cell and Systems Biology, Ramsay Wright Laboratories, University of Toronto, 25 Harbord Street, Toronto, Ontario M5S 3G5, Canada.
authors.forename: Rutsuko
authors.identifier: 0000-0003-1769-5470
authors.initials: R
authors.lastname: Ito
mesh_terms: D000818:Animals; D001245:Association Learning / Q000187:drug effects / Q000502:physiology; D001362:Avoidance Learning / Q000187:drug effects / Q000502:physiology*; D001418:Baclofen / Q000494:pharmacology; D002755:Choice Behavior / Q000187:drug effects / Q000502:physiology*; D003213:Conditioning, Psychological / Q000187:drug effects / Q000502:physiology; D003220:Conflict, Psychological; D003463:Cues; D018755:GABA Agonists / Q000494:pharmacology; D008297:Male; D009042:Motivation / Q000187:drug effects / Q000502:physiology; D009118:Muscimol / Q000494:pharmacology; D009714:Nucleus Accumbens / Q000187:drug effects / Q000502:physiology*; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism; D020318:Rats, Long-Evans; D011963:Receptors, GABA-A / Q000378:metabolism; D018080:Receptors, GABA-B / Q000378:metabolism; D055698:Touch Perception / Q000187:drug effects / Q000502:physiology; D014796:Visual Perception / Q000187:drug effects / Q000502:physiology
chemical_list: D018755:GABA Agonists; D016760:Proto-Oncogene Proteins c-fos; D011963:Receptors, GABA-A; D018080:Receptors, GABA-B; D009118:Muscimol; D001418:Baclofen
keywords: NAc; conditioned approach; conditioned avoidance; motivation; punishment; reward