Oberlin BG, Dzemidzic M, Tran SM, Soeurt CM, O’Connor SJ, Yoder KK, Kareken DA. Beer self-administration provokes lateralized nucleus accumbens dopamine release in male heavy drinkers.
Psychopharmacology (Berl) 2015;
232:861-70. [PMID:
25163422 PMCID:
PMC4326548 DOI:
10.1007/s00213-014-3720-1]
[Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Accepted: 08/11/2014] [Indexed: 10/24/2022]
Abstract
RATIONALE
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).
OBJECTIVES
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.
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