title: Preference for Cocaine is Represented in the Orbitofrontal Cortex by an Increased Proportion of Cocaine Use-Coding Neurons.
abstract: Cocaine addiction is a harmful preference for drug use over and at the expense of other nondrug-related activities. Here we identify in the rat orbitofrontal cortex (OFC) a mechanism that explains individual preferences between cocaine use and an alternative, nondrug action. OFC neuronal activity was recorded while rats performed each of these 2 actions separately or while they chose between them. First, we found that these actions are encoded by 2 nonoverlapping neuronal populations and that the relative size of the cocaine population represented individual preferences. A larger relative size was only observed in cocaine-preferring individuals. Second, OFC neurons encoding a given individual's preferred action progressively fired more than other action-coding neurons few seconds before the preferred action was actually chosen, suggesting a prechoice neuronal competition for action selection. In cocaine-preferring rats, this manifested by a prechoice ramping-up activity in favor of the cocaine population. Finally, pharmacological manipulation of prechoice activity in favor of the cocaine population caused nondrug-preferring rats to shift their choice to cocaine. Overall, this study suggests that an individual preference for cocaine is represented in the OFC by a population size bias that systematically advantages cocaine use-coding neurons during prechoice competition for action selection.
authors.affiliation: Université de Bordeaux, Institut des Maladies Neurodégénératives, UMR 5293, 146 rue Léo-Saignat, F-33000 Bordeaux, France.|CNRS, Institut des Maladies Neurodégénératives, UMR 5293, 146 rue Léo-Saignat, F-33000 Bordeaux, France.
authors.forename: Karine
authors.initials: K
authors.lastname: Guillem
authors.affiliation: Université de Bordeaux, Institut des Maladies Neurodégénératives, UMR 5293, 146 rue Léo-Saignat, F-33000 Bordeaux, France.|CNRS, Institut des Maladies Neurodégénératives, UMR 5293, 146 rue Léo-Saignat, F-33000 Bordeaux, France.
authors.forename: Serge H
authors.initials: SH
authors.lastname: Ahmed
mesh_terms: D000200:Action Potentials / Q000187:drug effects; D000779:Anesthetics, Local / Q000008:administration & dosage*; D000818:Animals; D002755:Choice Behavior / Q000187:drug effects / Q000502:physiology; D003042:Cocaine / Q000008:administration & dosage*; D003216:Conditioning, Operant / Q000187:drug effects*; D008297:Male; D009474:Neurons / Q000187:drug effects* / Q000502:physiology; D017397:Prefrontal Cortex / Q000166:cytology*; D051381:Rats; D017208:Rats, Wistar; D011930:Reaction Time / Q000187:drug effects; D012201:Reward; D012439:Saccharin / Q000008:administration & dosage
chemical_list: D000779:Anesthetics, Local; D012439:Saccharin; D003042:Cocaine
keywords: addiction; choice; cocaine; orbitofrontal cortex; preference