Cholinergic receptors

Cholinergic receptors are categorized as nicotinic and muscarinic by their responses to the alkaloids nicotine and muscarine, respectively. There are two main classes of nicotinic cholinergic receptors, muscular (found at the NMJ) and neuronal (found in autonomic ganglia, at end-organ sites of parasympathetic nerves, and in the central nervous system). Since the cholinergic receptors have different subunit composition, most drugs bind to them with different affinity and have different effects. Only ACh and drugs working by producing ACh (AChE inhibitors) are agonists at all of them.