A new inhibitor helps previously nicotine-addicted rats stay on the wagon, according to a study published on Oct. 22 in The Journal of Experimental Medicine.

Kicking the cigarette habit is difficult enough, but resisting the urge to light up in situations previously associated with smoking can be a quitter's downfall. But help may be at hand. A new inhibitor developed by Fang Liu and colleagues at the Centre for Addiction and Mental Health in Toronto helped ex-smoker rats resist that urge.

Liu and colleagues found that long-term nicotine exposure caused two neurotransmitter receptors to interact in the brain, and their inhibitor prevented this interaction. In rats trained to self-administer nicotine, the inhibitor had no effect on their propensity to indulge. But in "ex-smoker" rats (those weaned off nicotine), the inhibitor decreased the number of relapses after exposure to environmental cues previously associated with a nicotine fix.

If the inhibitor works the same way in humans, it may provide a powerful new way to reduce relapses in people who have quit smoking or chewing tobacco.