A PATCH CLAMP STUDY OF THE ACTION OF A NITROMETHYLENE HETEROCYCLE INSECTICIDE ON COCKROACH NEURONS GROWING INVITRO

The mode of action of a nitromethylene heterocycle (NMH) insecticide was studied by patch-clamp techniques using cockroach embryonic cultures as an experimental model. Under whole-cell recordings, this compound elicited inward currents resembling those induced by O-acetylcholine (ACh). The reversal potentials for both ACh and the NMH were similar, suggesting that the inward currents induced by both were carried by the same species of ion. Pharmacological investigations of NMH-induced responses revealed that the insecticidal action of this compound is exerted through agonistic action at the nicotinic acetylcholine receptor. Single-channel studies were also performed to study the interaction of NMH with the nicotinic-receptor-coupled ion channel.