title: Medial Prefrontal Cortical Dopamine Responses During Operant Self-Administration of Sweetened Ethanol.
abstract: Medial prefrontal cortex (mPFC) dysfunction is present in heavy alcohol consumers. Dopamine signaling in mPFC is associated with executive functioning and affects drinking behavior; however, direct measurement of extracellular mPFC dopamine during appetitive and consummatory ethanol (EtOH) self-administration behavior has not been reported.
  
  
  
  We used in vivo microdialysis in freely behaving, adult, male, Long Evans rats to determine extracellular dopamine concentration in the mPFC during operant self-administration of an EtOH-plus-sucrose or sucrose solution. The model separated appetitive/seeking from consummatory phases of the operant session. Dopamine was also monitored in an untrained handling control group, and dialysate EtOH was measured in the EtOH-drinking group.
  
  
  
  Home cage baseline dopamine was lower in rats that experienced a week of drinking sweetened EtOH compared with sucrose-drinking and handling controls. Transfer into the operant chamber and the initiation of consumption stimulated a relatively higher change in dopamine over baseline in the sweetened EtOH group compared with sucrose and handling controls. However, all groups show a dopamine response during transfer into the operant chamber, and the sucrose group had a relatively higher change in dopamine over baseline during initiation of consumption compared with handling controls. The time courses of dopamine and EtOH in the mPFC differ in the EtOH-consuming rats.
  
  
  
  Differences in extracellular mPFC dopamine between EtOH drinkers compared with control groups suggest that mPFC dopamine is involved in the mechanism of operant self-administration of sweetened EtOH and sucrose. Furthermore, the increase in dopamine during consumption is consistent with a role of mPFC dopamine in reward prediction.
authors.affiliation: Division of Pharmacology, College of Pharmacy, The University of Texas at Austin, Austin, Texas.
authors.forename: James M
authors.initials: JM
authors.lastname: Doherty
authors.affiliation: Division of Pharmacology, College of Pharmacy, The University of Texas at Austin, Austin, Texas.
authors.forename: Christina J
authors.initials: CJ
authors.lastname: Schier
authors.affiliation: Division of Pharmacology, College of Pharmacy, The University of Texas at Austin, Austin, Texas.
authors.forename: Ashley A
authors.initials: AA
authors.lastname: Vena
authors.affiliation: Division of Pharmacology, College of Pharmacy, The University of Texas at Austin, Austin, Texas.
authors.forename: Geoffrey A
authors.initials: GA
authors.lastname: Dilly
authors.affiliation: Division of Pharmacology, College of Pharmacy, The University of Texas at Austin, Austin, Texas.
authors.forename: Rueben A
authors.initials: RA
authors.lastname: Gonzales
mesh_terms: D000818:Animals; D003216:Conditioning, Operant / Q000187:drug effects / Q000502:physiology*; D004298:Dopamine / Q000378:metabolism*; D000431:Ethanol / Q000008:administration & dosage*; D008297:Male; D017397:Prefrontal Cortex / Q000187:drug effects / Q000378:metabolism*; D051381:Rats; D020318:Rats, Long-Evans; D012646:Self Administration; D013549:Sweetening Agents / Q000008:administration & dosage*
chemical_list: D013549:Sweetening Agents; D000431:Ethanol; D004298:Dopamine
keywords: Appetitive; Consumption; Ethanol; Ethanol-Seeking; Mesocortical; Operant Self-Administration