Researchers have found that injecting a new drug into the brains of rats causes them to lose interest in drinking alcohol almost immediately.

This may well point the way toward the development of a new class of drugs to treat alcoholism and, possibly, drug addiction.

Scientists from the University of California, San Francisco's Ernest Gallo Clinic and Research Center used a naturally-occurring brain protein called glial cell-derived neurotrophic factor (GDNF), which has also attracted investigative interest as a treatment for Parkinson's disease.

The study subjects were rats who had been conditioned to drink alcohol. Researchers injected GDNF into a part of the brain called the Ventral Tegmental Area, which in other studies has been shown to be involved in drug-seeking behavior.

The rats showed a markedly reduced interest in alcohol as soon as 10 minutes after being injected with GDNF.

An added benefit was that GDNF did not interfere with other pleasure-seeking behaviors (such as the desire to eat sweets), a common side effect of other anti-addiction drugs.

"There is tremendous need for therapies to treat alcohol abuse," study senior author Dorit Ron said in a prepared statement, "Unfortunately, only three drugs are currently approved to treat excessive drinking, and all have serious limitations. Our findings open the door to a promising new strategy to combat alcohol abuse, addiction and especially relapse.

The study was published in the June 10 issue of the Proceedings of the National Academy of Sciences.