Chrna6, encoding the α6 subunit of nicotinic acetylcholine receptors (nAChR), is a gene with significant biological importance. nAChRs are ligand-gated ion channels involved in the cholinergic modulation of neurotransmitter release, especially dopamine release in the striatum. The CHRNB3-Chrna6 gene cluster on chromosome 8 has been shown to play crucial roles in nicotine dependence [1].

Functional studies in mice have demonstrated that α6 *-nAChRs located in the ventral tegmental area (VTA) are important in controlling nicotine self-administration. When the α6 subunit is selectively re-expressed in the VTA of the α6(-/-) mouse by a lentiviral vector, the reinforcing property of nicotine is restored. Also, replacement of Leu with Ser in the 9' residue in the M2 domain of α6 in genetic knock-in strains produces nicotine-hypersensitive mice with enhanced dopamine release [1]. In a child with severe infantile parkinsonism, a de novo missense mutation in Chrna6 was considered as a genetic modifier contributing to the phenotype, and in vitro and in vivo analyses demonstrated disruptive effects of the mutation on acetylcholine receptor structure and function [2].

In conclusion, Chrna6 is essential for the normal function of nAChRs, especially in processes related to nicotine dependence and dopamine release. Mouse models, such as gene knockout and knock-in models, have provided valuable insights into Chrna6's role in nicotine-related behaviors and in certain neurological phenotypes like infantile parkinsonism. Understanding Chrna6 may offer potential strategies for treating nicotine addiction and related neurological disorders.