Summary: A new neuroimaging study links alcohol cravings to the right ventral striatum.
Source: Indiana University
If you really want a drink right now, the source of your craving may be a pea-sized structure deep inside the right side of your brain, according to scientists at the Indiana University School of Medicine.
Using two different kinds of advanced brain imaging techniques (PET and fMRI), the researchers compared the results of giving beer drinkers a taste of their favorite beer versus a sports drink. After tasting the beer the participants reported increased desire to drink beer, whereas the sports drink did not provoke as much desire for beer. The brain scans also showed that the beer flavor induced more activity in both frontal lobes and in the right ventral striatum of the subjects’ brains than did the sports drink.
More specifically, both methods of brain imaging showed increased activity in the right ventral striatum, a deep structure inside the brain that is linked to motivated behavior and reward. The researchers previously showed that beer flavor triggered dopamine release; the addition of fMRI showed that craving for alcohol correlated with frontal as well as right ventral striatum activation. The study was published recently in the journal Alcoholism: Clinical and Experimental Research.
In an earlier study of 49 men, the research team, led by David A. Kareken, Ph.D., professor of neurology at the IU School of Medicine and the deputy director of the Indiana Alcohol Research Center, found that just the taste of beer, without any intoxicating effects of alcohol, was enough to cause the release of dopamine, a brain neurotransmitter. Much research has linked dopamine to consumption of drugs of abuse.
The new study was conducted with 28 beer drinkers who had participated in the first study, who then underwent functional magnetic resonance imaging – fMRI scans – during the separate beer and Gatorade tastings.
“We believe this is the first study to use multiple brain imaging modalities to reveal both increased blood oxygen levels and dopamine activity in response to the taste of an alcoholic beverage,” said Brandon G. Oberlin, Ph.D., assistant research professor of neurology and first author of the paper. “The combination of these two techniques in the same subjects strengthens the evidence that these effects may be strongest in the right ventral striatum.
“Our results indicate that the right ventral striatum may be an especially important area for addiction research,” Dr. Oberlin said.
In addition to Drs. Oberlin and Kareken, investigators contributing to the research were Mario Dzemidzic, Jaroslaw Harezlak, Maria A. Kudela, Stella M. Tran, Christina M. Soeurt and Karmen K. Yoder of the IU School of Medicine.
Funding: The research was supported by grants from the National Institutes of Health, R01AA017661-01A1S1, T32AA007462 and K99AA023296, as well as the Indiana Alcohol Research Center (P60AA07611), the Indiana Clinical and Translational Sciences Institute Clinical Research Center, UL1TR001108, NIH, National Center for Advancing Translational Sciences, Clinical and Translational Sciences Award.
Source: Eric Schoch – Indiana University
Image Source: NeuroscienceNews.com image is credited to B. Oberlin and D. Kareken, Indiana University School of Medicine.
Original Research: Abstract for “Corticostriatal and Dopaminergic Response to Beer Flavor with Both fMRI and [11C]raclopride Positron Emission Tomography” by Brandon G. Oberlin, Mario Dzemidzic, Jaroslaw Harezlak, Maria A. Kudela, Stella M. Tran, Christina M. Soeurt, Karmen K. Yoder and David A. Kareken in Alcoholism: Clinical & Experimental Research. Published online July 26 2016 doi:10.1111/acer.13158
Corticostriatal and Dopaminergic Response to Beer Flavor with Both fMRI and [11C]raclopride Positron Emission Tomography
Cue-evoked drug-seeking behavior likely depends on interactions between frontal activity and ventral striatal (VST) dopamine (DA) transmission. Using [11C]raclopride (RAC) positron emission tomography (PET), we previously demonstrated that beer flavor (absent intoxication) elicited VST DA release in beer drinkers, inferred by RAC displacement. Here, a subset of subjects from this previous RAC-PET study underwent a similar paradigm during functional magnetic resonance imaging (fMRI) to test how orbitofrontal cortex (OFC) and VST blood oxygenation level-dependent (BOLD) responses to beer flavor are related to VST DA release and motivation to drink.
Male beer drinkers (n = 28, age = 24 ± 2, drinks/wk = 16 ± 10) from our previous PET study participated in a similar fMRI paradigm wherein subjects tasted their most frequently consumed brand of beer and Gatorade® (appetitive control). We tested for correlations between BOLD activation in fMRI and VST DA responses in PET, and drinking-related variables.
Compared to Gatorade, beer flavor increased wanting and desire to drink, and induced BOLD responses in bilateral OFC and right VST. Wanting and desire to drink correlated with both right VST and medial OFC BOLD activation to beer flavor. Like the BOLD findings, beer flavor (relative to Gatorade) again induced right VST DA release in this fMRI subject subset, but there was no correlation between DA release and the magnitude of BOLD responses in frontal regions of interest.
Both imaging modalities showed a right-lateralized VST response (BOLD and DA release) to a drug-paired conditioned stimulus, whereas fMRI BOLD responses in the VST and medial OFC also reflected wanting and desire to drink. The data suggest the possibility that responses to drug-paired cues may be rightward biased in the VST (at least in right-handed males) and that VST and OFC responses in this gustatory paradigm reflect stimulus wanting.
“Corticostriatal and Dopaminergic Response to Beer Flavor with Both fMRI and [11C]raclopride Positron Emission Tomography” by Brandon G. Oberlin, Mario Dzemidzic, Jaroslaw Harezlak, Maria A. Kudela, Stella M. Tran, Christina M. Soeurt, Karmen K. Yoder and David A. Kareken in Alcoholism: Clinical & Experimental Research. Published online July 26 2016 doi:10.1111/acer.13158