How are nicotinic cholinergic receptors?

Bind acetyl choline and recognize nicotine, weak affinity to muscarine, 5 subunits, ligand gated ion channels always cause rapid increase in cellular permeability to Na+ (depolarization) and Ca2+ (excitation) Located in CNS, Adrenal medulla (NN), autonomic ganglia (NG), and neuromuscular jucntions (NM) Those of autonomic ganglia differ from those of neuromuscular, ganglionic are blocked by hexamethonium whereas neuromuscular are blocked by tubocurarine.