Genes EncodingNeuronal NicotinicAcetyicholineReceptors

Four genes (alpha2, aIpha3, alpha4, and beta2), which encode proteins homologous to the Torpedoelectric organ and vertebrate muscle nicotinic acetylcholine receptors, have been identified by cloning rat brain cDNAs. Injection of transcripts derived from these cDNAs into Xenopus !aevis oocytes results in the formation of three nicotinic acetylcholine receptors. Two of these receptors, alpha3/beta2 and alpha4/beta2, have the characteristics of ganglionic nicotinic receptors. The third (alpha2/beta2) exhibits a previously undescribed pharmacology and thus represents a novel subtype that may be expressed in the brain. The wide distribution of alpha2, alpha3, alpha4, and beta2 transcripts in the brain indicates that neuronal nicotinic acetyicholine receptors are a major neurotransmitter receptor system.