A new study of animal brains shows that subtle differences in brain circuitry can explain why some animals become addicted to nicotine and others do not. Scientists at the University of Western Ontario have also been able to reverse this process and make nicotine unpleasant to rats formerly addicted to it.

Studies published last year found that some teenagers could become smokers after just one experimental cigarette while others find the experience unpleasant. The Canadian animal studies indicate that the key to understanding why this happens may have to do with "nucleus accumbens" or areas in the reward circuitry of the brain.

Dr. Steven Laviolette, writing in the journal Neuroscience, said, "If we can develop pharmacological treatments to target those regions, we can basically affect the development of nicotine addiction by controlling the brain's perception of nicotine's rewarding effects."

Labels: addiction, medications, prevention