Muscarinic cholinergic binding sites in an orthopteran central nervous system.

Homogenates of cricket (Acheta domesticus) central nervous system (CNS) specifically bind to potent muscarinic ligand [3H]-QNB. Binding assay and pharmacologic data indicate that the cricket CNS contains a high density of muscarinic cholinergic binding sites. These sites appear to be a unique class of invertebrate cholinergic receptor with properties distinct from those of previously described nicotinic receptors.