Alcohol sensitizes cerebral responses to the odors of alcoholic drinks: an fMRI study.
BACKGROUND
Small, priming doses of alcohol enhance desire to drink, and thus play a role in the loss of control of alcohol consumption. Using functional magnetic resonance imaging (fMRI), we previously showed that alcoholic drink odors (AO; subjects' drinks of choice) induce greater nucleus accumbens (NAc) activity than non-appetitive odors (NApO; grass, leather) in subjects at risk for alcoholism. Here we hypothesized that priming exposure to alcohol would enhance responses to AO in the NAc and orbitofrontal cortex in comparison to NApO (grass, leather) and to the appetitive control odors (ApCO) of chocolate and grape.


METHODS
Ten hazardous drinkers (mean age = 22.7; SD = 2.9, average drinks per drinking day = 5.9, SD = 2.3; drinking days/90 days = 50.4, SD = 13.7) were scanned on a 1.5 T GE Signa MR scanner during intravenous infusion of lactated Ringer's or 6% ethanol in lactated Ringer's that was pharmacokinetically modeled to achieve a constant breath alcohol concentration (BrAC) of 50 mg% throughout imaging. During scanning, subjects sniffed AO, NApO, and ApCO.


RESULTS
Alcohol infusion enhanced the contrast between AO and NApO in the NAc, and in orbitofrontal, medial frontal, and precuneus/posterior cingulate regions. The contrast between AO and appetitive control odors (ApCO; chocolate and grape) was similarly larger in the orbital, medial frontal, precuneus, and posterior cingulate/retrosplenial areas, with the most robust finding being a potentiated response in the posterior cingulate/retrosplenial area. The orbital region is similar to an area previously shown to manifest satiety-related decreases in activity induced by food cues.


CONCLUSIONS
The results suggest that priming exposure to alcohol renders a limbic network more responsive to alcohol cues, potentially enhancing desire to drink.
Department of Neurology, Indiana University School of Medicine, Indianapolis, Indiana 46202, USA.
Veronique
V
Bragulat
Mario
M
Dzemidzic
Thomas
T
Talavage
Dena
D
Davidson
Sean J
SJ
O'Connor
David A
DA
Kareken
D000328:Adult; D000339:Affect; D000428:Alcohol Drinking / Q000503:physiopathology*; D001944:Breath Tests; D002492:Central Nervous System Depressants / Q000008:administration & dosage*; D000431:Ethanol / Q000008:administration & dosage*; D005260:Female; D005625:Frontal Lobe / Q000503:physiopathology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009714:Nucleus Accumbens / Q000503:physiopathology*; D009812:Odorants; D012903:Smell
D002492:Central Nervous System Depressants; D000431:Ethanol