Nicotinic acetylcholine receptors

Nicotinic receptors (nAChRs) are ligand-gated ion channels that respond to acetylcholine and modulate cell membrane potentials.  Nicotinic receptors are pentamers, with each receptor being composed of combinations of  the subunits α1-10, β1-4, δ, ε and γ. Nicotinic receptors are divided into three functional classes: muscle subunits (α1, β1, δ, ε, γ), standard neuronal subunits (α1-6 and β2-4) - that form in pairwise αβ combinations - and subunits (α7-9) that can form homomeric nAChRs.  Nicotinic receptors regulate the flow of mainly sodium, potassium and calcium ions across cell membranes and are found in the central and peripheral nervous system, muscle, and many other tissues of many organisms, where they regulate processes such as transmitter release, cell excitability and neuronal integration.  Nicotinic receptors located at the neuromuscular junctions of somatic muscles are responsible for muscular contraction.

Further reading

Papke (2014) Merging old and new perspectives on nicotinic acetylcholine receptors. Biochem Pharmacol. 89(1) 1 PMID: 24486571

Dineley et al (20215) Nicotinic ACh receptors as therapeutic targets in CNS disorders. Trends Pharmacol Sci. 36(2) 96 PMID: 25639674

Ho et al (2020) Structure-Function of Neuronal Nicotinic Acetylcholine Receptor Inhibitors Derived From Natural Toxins. Front Neurosci. 4 609005 PMID: 33324158