Alcohol promotes dopamine release in the human nucleus accumbens.
Microdialysis experiments in rodents indicate that ethanol promotes dopamine release predominantly in the nucleus accumbens, a phenomenon that is implicated in the reinforcing effects of drugs of abuse. The aim of the present study was to test the hypothesis in humans that an oral dose of ethanol would lead to dopamine release in the ventral striatum, including the nucleus accumbens. Six healthy subjects underwent two [(11)C]raclopride PET scans following either alcohol (1 ml/kg) in orange juice or orange juice alone. Subjective mood changes, heart rate, and blood-alcohol levels were monitored throughout the procedure. Personality traits were evaluated using the tridimensional personality questionnaire. PET images were co-registered with MRI and transformed into stereotaxic space. Statistical parametric maps of [(11)C]raclopride binding potential change were generated. There was a significant reduction in [(11)C]raclopride binding potential bilaterally in the ventral striatum/nucleus accumbens in the alcohol condition compared to the orange juice condition, indicative of increased extracellular dopamine. Moreover, the magnitude of the change in [(11)C]raclopride binding correlated with the alcohol-induced increase in heart rate, which is thought to be a marker of the psychostimulant effects of the drug, and with the personality dimension of impulsiveness. The present study is the first report that, in humans, alcohol promotes dopamine release in the brain, with a preferential effect in the ventral striatum. These findings support the hypothesis that mesolimbic dopamine activation is a common property of abused substances, possibly mediating their reinforcing effects.
Boileau
Isabelle
I
McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, 3801 University Street, Montréal, Quebec, Canada H3A 2B4.
Assaad
Jean-Marc
JM
Pihl
Robert O
RO
Benkelfat
Chawki
C
Leyton
Marco
M
Diksic
Mirko
M
Tremblay
Richard E
RE
Dagher
Alain
A
D000328:Adult; D000428:Alcohol Drinking / Q000378:metabolism*; D001479:Basal Ganglia / Q000187:drug effects / Q000378:metabolism; D002492:Central Nervous System Depressants / Q000494:pharmacology; D004298:Dopamine / Q000378:metabolism*; D018492:Dopamine Antagonists; D000431:Ethanol / Q000494:pharmacology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009714:Nucleus Accumbens / Q000187:drug effects* / Q000378:metabolism*; D020891:Raclopride; D014055:Tomography, Emission-Computed
D002492:Central Nervous System Depressants; D018492:Dopamine Antagonists; D000431:Ethanol; D020891:Raclopride; D004298:Dopamine