Nicotinic acetylcholine receptors (nAChRs) are cholinergic receptors that form ligand-gated ion channels that mediate fast signal transmission at synapses. CHRNA7 (neuronal acetylcholine receptor subunit alpha-7) forms a homo-oligomeric channel,displays marked permeability to calcium ions and is a major component of brain nicotinic receptors that are blocked by,and highly sensitive to,alpha-bungarotoxin.