Super Agonist Actions of Clothianidin and Related Compounds on the SADβ2 Nicotinic Acetylcholine Receptor Expressed in Xenopus laevis Oocytes

Abstract

To compare the actions of clothianidin, a neonicotinoid acting on insect nicotinic acetylcholine receptors, and related compounds with that of imidacloprid, the compounds were tested on the Drosophila SAD-chicken β2 nicotinic acetylcholine receptor expressed in Xenopus laevis oocytes using two-electrode voltage-clamp electrophysiology. The maximum response of the SADβ2 nicotinic receptor to clothianidin was larger than that observed for acetylcholine. Ring breakage of the imidazolidine ring of imidacloprid resulting in the generation of a guanidine group was critical for this super agonist action.