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.
Describes research results reporting that people who favor novelty have lower-than-average availability of a receptor that inhibits dopamine's release from neurons, which likely stimulates the activity of reward circuits.
Exposing rats to THC increases the likelihood that the animals will later self-administer nicotine. THC-exposed rats are also willing to work harder to obtain nicotine. When extrapolated to people, the findings suggest that THC’s pharmacological impact on the brain may make a person who uses marijuana more vulnerable to developing nicotine addiction, an underappreciated health consequence of marijuana use.