The Journal of Young Investigators: An Undergraduate, Peer-Reviewed Science Journal

15 December 2004 - The chemical that enhances a desire for food and alcohol may also be linked to chronic drinking, according to a Princeton University study. The research, conducted by Bartley Hoebel, professor of psychology, and Michael Lewis, visiting research fellow and a senior fellow of the National Institute on Alcohol Abuse and Alcoholism (NIAAA), will be published in the December issue of Alcoholism: Clinical and Experimental Research.

Hoebel, Lewis and their colleagues injected rats with the neuropeptide galatin, a natural signaling agent in the brain known to trigger hunger. The team found that the injected rats chose to drink an increased amount of alcohol, even when they received adequate food and water. When the animals were given injections that prevented the effects of galanin, their eating habits returned to normal.

"There seems to be a cycle of positive feedback," said Hoebel, "Consumption of alcohol produces galanin, and galanin promotes the consumption of alcohol.”

A similar cycle exists between gelanin and fatty foods. In the article, Hoebel and Lewis explain that eating fatty foods causes a part of the brain to produce more galanin, resulting in an appetite increase for fatty foods. Normally, a person has counteracting signals that break this loop. The researchers believe their results are evidence of a neurological connection between food and alcohol desire.

"Alcohol is the only drug of abuse that is also a calorie-rich food, and it undoubtedly has important interactions with systems that control food intake and nutrition," said Lewis.

The researchers hope the study will help create a drug that fights alcoholism by blocking galanin. Creating substances that move through the blood, into the brain and interact with neuropeptide receptors like galanin, however, is quite difficult. In addition, such a drug could block galanin’s other functions in the brain. Lewis and Hoebel plan to explore possible links between other neuropeptides and alcohol consumption.

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