Smoking

Nicotine sensitizes the mouse brain to the addictive effects of cocaine, according to recent NIDA-supported research. The results accord with the hypothesis that a person’s initial use of an addictive substance physiologically sensitizes his or her brain to the rewarding and addictive effects of other substances. If the findings carry over to people, then preventing youths from smoking might reduce their vulnerability to cocaine abuse and addiction, and cocaine-dependent individuals might ease their path to recovery by quitting smoking.

New research suggests that differences in tobacco consumption reflect, in part, differences in the functional efficacy of a specific type of receptor in a pathway of the brain. In animal studies, nicotinic acetylcholine receptors with the α5 subunit played a key role in producing aversive responses to nicotine, thereby dissuading further consumption of the drug.