title: Beer self-administration provokes lateralized nucleus accumbens dopamine release in male heavy drinkers.
abstract: BACKGROUND
  Although striatal dopamine (DA) is important in alcohol abuse, the nature of DA release during actual alcohol drinking is unclear, since drinking includes self-administration of both conditioned flavor stimuli (CS) of the alcoholic beverage and subsequent intoxication, the unconditioned stimulus (US).
  
  
  OBJECTIVE
  Here, we used a novel self-administration analog to distinguish nucleus accumbens (NAcc) DA responses specific to the CS and US.
  
  
  METHODS
  Right-handed male heavy drinkers (n = 26) received three positron emission tomography (PET) scans with the D2/D3 radioligand [(11)C]raclopride (RAC) and performed a pseudo self-administration task that separately administered a flavor CS of either a habitually consumed beer or the appetitive control Gatorade®, concomitant with the US of ethanol intoxication (0.06 g/dL intravenous (IV) administration) or IV saline. Scan conditions were Gatorade flavor + saline (Gat&Sal), Gatorade flavor + ethanol (Gat&Eth), and beer flavor + ethanol (Beer&Eth).
  
  
  RESULTS
  Ethanol (US) reduced RAC binding (inferring DA release) in the left (L) NAcc [Gat&Sal > Gat&Eth]. Beer flavor (CS) increased DA in the right (R) NAcc [Gat&Eth > Beer&Eth]. The combination of beer flavor and ethanol (CS + US), [Gat&Sal > Beer&Eth], induced DA release in bilateral NAcc. Self-reported intoxication during scanning correlated with L NAcc DA release. Relative to saline, infusion of ethanol increased alcoholic drink wanting.
  
  
  CONCLUSIONS
  Our findings suggest lateralized DA function in the NAcc, with L NAcc DA release most reflecting intoxication, R NAcc DA release most reflecting the flavor CS, and the conjoint CS + US producing a bilateral NAcc response.
authors.affiliation: Department of Neurology, Indiana University School of Medicine (IUSOM), 355 W 16th St. Ste 4600, Indianapolis, IN, 46202, USA.
authors.forename: Brandon G
authors.initials: BG
authors.lastname: Oberlin
authors.forename: Mario
authors.initials: M
authors.lastname: Dzemidzic
authors.forename: Stella M
authors.initials: SM
authors.lastname: Tran
authors.forename: Christina M
authors.initials: CM
authors.lastname: Soeurt
authors.forename: Sean J
authors.initials: SJ
authors.lastname: O'Connor
authors.forename: Karmen K
authors.initials: KK
authors.lastname: Yoder
authors.forename: David A
authors.initials: DA
authors.lastname: Kareken
mesh_terms: D000328:Adult; D000435:Alcoholic Intoxication / Q000000981:diagnostic imaging / Q000378:metabolism*; D001515:Beer; D003213:Conditioning, Psychological / Q000187:drug effects; D003342:Corpus Striatum / Q000000981:diagnostic imaging / Q000187:drug effects / Q000378:metabolism; D004298:Dopamine / Q000378:metabolism*; D018492:Dopamine Antagonists / Q000494:pharmacology; D000431:Ethanol / Q000008:administration & dosage*; D006801:Humans; D008297:Male; D009714:Nucleus Accumbens / Q000000981:diagnostic imaging / Q000187:drug effects* / Q000378:metabolism; D020891:Raclopride / Q000494:pharmacology; D011877:Radionuclide Imaging; D012646:Self Administration; D055815:Young Adult
chemical_list: D018492:Dopamine Antagonists; D000431:Ethanol; D020891:Raclopride; D004298:Dopamine