http://www.newscientist.com/article.ns?id=...line-news_rss20

'Rats addicted to amphetamines temporarily 'forget' their drug cravings after receiving targeted brain injections of lidocaine, a medication commonly used by dentists to numb patients' gums.

Researchers say that the medication worked by inactivating an area of the brain known as the insular cortex or insula, which has previously been implicated in controlling drug addiction. They hope that altering activity in the insula might one day work to treat drug addiction in people. Other experts, however, note that addiction is a complex problem that seems to involve multiple brain regions.

Previous research has shown that brain regions such as the prefrontal cortex and nucleus accumbens drive drug cravings by responding to reward signals from the chemical dopamine in the brain.

But Fernando Torrealba at the Pontifical Catholic University of Chile in Santiago believed that the insula, a brain region located behind the ears, might somehow exert a large influence on addiction. The insula appears to monitor the body's heart rate, blood sugar, and other functions, and prompt conscious feelings of hunger and cravings in response. Recent work has shown that damage to this area can cause smokers to give up cigarettes overnight.'