title: Prefrontal Regulation of Neuronal Activity in the Ventral Tegmental Area.
abstract: Growing evidence indicates that midbrain dopamine (DA) cells integrate reward expectancy-related information from the prefrontal cortex to properly compute errors in reward prediction. Here we investigated how 2 major prefrontal subregions, the orbitofrontal cortex (OFC) and the medial prefrontal cortex (mPFC), contributed to DAergic prediction errors while rats performed a delay discounting task on a T-maze. Most putative DA cells in the task showed phasic responses to salient cues that predicted delayed rewards, but not to the actual rewards. After temporary inactivation of the OFC, putative DA cells exhibited strikingly reduced phasic responses to reward-predicting cues but increased responses to rewards. In contrast, mPFC inactivation significantly elevated DA responses to both predictive cues and rewards. In addition, OFC, but not mPFC, inactivation disrupted the activity of putative non-DA cells that encoded expected reward values during waiting periods. These results suggest that the 2 prefrontal subregions differentially regulate DAergic prediction errors and the OFC conveys value signals to midbrain dopamine systems.
authors.affiliation: Department of Psychology, University of Washington, Seattle, WA, USA.
authors.forename: Yong Sang
authors.initials: YS
authors.lastname: Jo
authors.affiliation: Department of Psychology, University of Washington, Seattle, WA, USA.|Neuroscience Program, University of Washington, Seattle, WA 98195, USA.
authors.forename: Sheri J Y
authors.initials: SJY
authors.lastname: Mizumori
mesh_terms: D000200:Action Potentials; D000818:Animals; D059031:Anticipation, Psychological / Q000502:physiology*; D002408:Catheters, Indwelling; D065786:Delay Discounting / Q000502:physiology*; D059290:Dopaminergic Neurons / Q000187:drug effects / Q000502:physiology*; D004567:Electrodes, Implanted; D058785:GABA-A Receptor Agonists / Q000494:pharmacology; D008297:Male; D018782:Maze Learning / Q000502:physiology; D008845:Microinjections; D009118:Muscimol / Q000494:pharmacology; D017397:Prefrontal Cortex / Q000187:drug effects / Q000502:physiology*; D020318:Rats, Long-Evans; D012201:Reward; D017557:Ventral Tegmental Area / Q000502:physiology*
chemical_list: D058785:GABA-A Receptor Agonists; D009118:Muscimol
keywords: decision-making; delay discounting; dopamine; orbitofrontal cortex; prefrontal cortex