PET and fMRI imaging revealed that the source of alcohol cravings may be a pea-sized structure deep in the right side of the brain. A team of scientists at the Indiana University School of Medicine have established that the right brain may be particularly important for addiction research.

For the study, beer drinkers were given a taste of their favorite beer and then a sports drink while undergoing PET and fMRI scans. The participants reported a stronger desire to drink beer after tasting it, but the sports drink didn't lead to as much of a desire for beer.

The scans showed that the beer induced more activity in both frontal lobes and in the right ventral striatum of the participants brains than the sports drink. The right ventral striatum is part of the brain that's associated with motivated behavior and reward.
In a previous study that involved 49 men, the researchers found that just the taste of beer without any of the intoxicating effects of alcohol caused a release of the brain neurotransmitter, dopamine. The new study included 28 beer drinkers who were involved in the first study.

"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, assistant research professor of neurology and first author of the paper, in a statement.

"The combination of these two techniques in the same subjects strengthens the evidence that these effects may be strongest in the right ventral striatum," he added.

At this year's SNMMI annual meeting, a study was presented that provided additional new insight on the physical and neurological nature of addiction. The researchers used PET/CT to understand the connection between the mGluR5 brain receptor associated with reward and pleasure and the compulsion to drink.

“This research is the first to provide direct in vivo evidence that mGluR5 is involved in the pathophysiology of alcohol addiction,” Dr. Gil Leurquin-Sterk, first author of the study and physician at the University Hospital Gasthuisberg in Leuven, Belgium, told HCB News. “Before this development, direct human evidence of its involvement in addiction was lacking and only suggested by animal models.”

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