title: Individual differences in impulsive action and dopamine transporter function in rat orbitofrontal cortex.
abstract: Impulsivity, which can be subdivided into impulsive action and impulsive choice, is implicated as a factor underlying drug abuse vulnerability. Although previous research has shown that dopamine (DA) systems in prefrontal cortex are involved in impulsivity and substance abuse, it is not known if inherent variation in DA transporter (DAT) function contributes to impulsivity. The current study determined if individual differences in either impulsive action or impulsive choice are related to DAT function in orbitofrontal (OFC) and/or medial prefrontal cortex (mPFC). Rats were first tested both for impulsive action in a cued go/no-go task and for impulsive choice in a delay-discounting task. Following behavioral evaluation, in vitro [(3)H]DA uptake assays were performed in OFC and mPFC isolated from individual rats. Vmax in OFC, but not mPFC, was correlated with performance in the cued go/no-go task, with decreased OFC DAT function being associated with high impulsive action. In contrast, Vmax in OFC and mPFC was not correlated with performance in the delay-discounting task. The current results demonstrate that impulsive behavior in cued go/no-go performance is associated with decreased DAT function in OFC, suggesting that hyperdopaminergic tone in this prefrontal subregion mediates, at least in part, increased impulsive action.
authors.affiliation: Department of Psychology, University of Kentucky, Lexington, KY 40536, USA; Department of Psychological Science, Northern Kentucky University, Highland Heights, KY 41099, USA.
authors.forename: J R
authors.initials: JR
authors.lastname: Yates
authors.affiliation: Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, Lexington, KY 40536, USA; Center for Drug Abuse Research Translation, University of Kentucky, Lexington, KY 40536, USA.
authors.forename: M
authors.initials: M
authors.lastname: Darna
authors.affiliation: Department of Psychology, University of Kentucky, Lexington, KY 40536, USA.
authors.forename: J S
authors.initials: JS
authors.lastname: Beckmann
authors.affiliation: Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, Lexington, KY 40536, USA; Center for Drug Abuse Research Translation, University of Kentucky, Lexington, KY 40536, USA.
authors.forename: L P
authors.initials: LP
authors.lastname: Dwoskin
authors.affiliation: Department of Psychology, University of Kentucky, Lexington, KY 40536, USA; Center for Drug Abuse Research Translation, University of Kentucky, Lexington, KY 40536, USA. Electronic address: mbardo@email.uky.edu.
authors.forename: M T
authors.initials: MT
authors.lastname: Bardo
mesh_terms: D000818:Animals; D003216:Conditioning, Operant / Q000502:physiology; D065786:Delay Discounting / Q000502:physiology*; D004298:Dopamine / Q000378:metabolism; D050483:Dopamine Plasma Membrane Transport Proteins / Q000378:metabolism*; D007175:Impulsive Behavior / Q000502:physiology*; D007206:Individuality; D008297:Male; D009483:Neuropsychological Tests; D017397:Prefrontal Cortex / Q000378:metabolism*; D011597:Psychomotor Performance / Q000502:physiology*; D011863:Radioimmunoassay; D019275:Radiopharmaceuticals; D017207:Rats, Sprague-Dawley; D014316:Tritium
chemical_list: D050483:Dopamine Plasma Membrane Transport Proteins; D019275:Radiopharmaceuticals; D014316:Tritium; D004298:Dopamine
keywords: cued go/no-go; delay discounting; dopamine transporter; impulsive action; impulsive choice; rat