Acetylcholine receptors (AChRs) mediate synaptic transmission at the neuromuscular junction. The channel-linked AChR that mediates rapid, excitatory actions of acetylcholine is called nicotinic AChR (nAChR) because it can be activated by nicotine. The non-channel linked AChR that medicates the slow actions of acetylcholine, which can be either inhibitory or excitatory, is called muscarinic AChR (mAChR) because it can be activated by muscarine.
The nAChRs fall into two subclasses, the muscle-type and the neuronal-type. The muscle-type receptor is a pentameric glycoprotein of five membrane spanning subunits, (2 alpha 1's, beta 1, gamma or epsilon and delta) which form a ligand gated ion channel. The neuronal nAChR is also a pentamer, but unlike the muscle-type, is made up of only two general types of subunits, alpha and beta of which multiple subtypes have been described (alpha 2 to alpha 8 and beta 2 to beta 4).
Acetylcholine receptor subunit alpha; acetylcholine receptor, nicotinic, alpha 1 (muscle); alpha-1 subunit, nicotinic acetylcholine receptor; cholinergic receptor nicotinic alpha polypeptide 1; cholinergic receptor, nicotinic alpha 1; cholinergic receptor, nicotinic, alpha 1 (muscle); cholinergic receptor, nicotinic, alpha polypeptide 1 (muscle); muscle nicotinic acetylcholine receptor; nAChR; nicotinic acetylcholine receptor alpha subunit; nicotinic cholinergic receptor alpha 1