Drugs can alter the way people think, feel, and behave by disrupting neurotransmission, the process of communication between brain cells. This article discusses the central importance of studying drugs’ effects on neurotransmission and describes some of the most common experimental methods used in this research.
March 2012 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.
April 2009 Describes findings from an animal study showing that cocaine lowers availability of dopamine receptors in the basal ganglia, an area of the brain that includes portions of the reward system.
October 2010 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.
April 2014 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.
Methamphetamine alters brain structures involved in decision-making and impairs the ability to suppress habitual behaviors that have become useless or counterproductive. The two effects were correlated, indicating that the structural change underlies the decline in mental flexibility.