[Nicotine dependence and its molecular pharmacology].

Mounting evidence indicates that addictive effects of nicotine occur through interaction with its receptors in the mesolimbic dopamine system, particularly ventral tegmental area neurons, where nicotinic acetylcholine receptors (nAChRs) act to promote the release of dopamine. Indeed chronic treatment with nicotine leads to an up-regulation in the number of alpha4beta2-subunit nAChRs. Moreover, N-methyl-D-aspartate receptors and gamma-aminobutyric acid receptors are also involved in the regulation of dopamine release.