The role of neuronal nicotinic acetylcholine receptor subunits in autonomic ganglia: lessons from knockout mice

Neuronal nicotinic acetylcholine receptors (nAChR), composed of 12 subunits (alpha2-alpha10, beta2-beta4), are expressed in autonomic ganglia, playing a central role in autonomic transmission. The repertoire of nicotinic subunits in autonomic ganglia includes alpha3, alpha5, alpha7, beta2 and beta4 subunits. In the last 10 years, heterologous expression studies have revealed much about the nature of neuronal nAChRs. However, there is only limited understanding of subunit actions in autonomic system. Functional deletions of subunit by gene knockout in animals could overcome these limitations. We review recent studies on nAChRs on autonomic ganglia for physiological and pharmacological properties and potential locations of the subunits.