[Involvement of neuronal nicotinic receptor in psychiatric disorders]

Neuronal nicotinic acetylcholine receptors (nAChR) are a family of ligand-gated ion channels that have a pentameric structure composed of five membrane spanning subunits. Recent progress in clinical and neurochemical studies have shown that neuronal nAChR are involved in some psychiatric disorders such as schizophrenia, depression, and anxiety via its stimulating effect of multiple neurotransmitters. It has been suggested that the high prevalence of smoking in the patients with psychiatric disorders is an attempt to alleviate some psychiatric symptoms using the central stimulatory effect of nicotine (a self-medication effort) or to alleviate the exacerbated symptoms by nicotine withdrawal. Moreover, recent studies with mutant mice lacking specific nAChR subunits and animal models of psychiatric disorders have indicated the psychopharmacological role of individual nAChR subunits in psychiatric disorders. Thus, it is suggested that alpha 7 nAChR is involved in the attention deficit of schizophrenic patients and that alpha 4 beta 2 nAChR is related to nicotine dependence or the withdrawal symptoms.