INFLUENCE OF NEUROTRANSMISSION IN FROG PERIPHERAL NERVE BY THE NEONICOTINOID INSECTICIDE IMIDACLOPRID: AN ELECTROPHYSIOLOGICAL STUDY

摘要

In this study, the effects of a neonicotinoid insecticide, imidacloprid, and the effects of nicotinic acetylcho-line receptor antagonists, α-bungarotoxin or mecamylamine (10 μM), on the action potential of the frogs sciatic nerve in the presence of imidacloprid (0.01, 0.1, 1, 10, 100, and 1000 μM) were examined by means of the electrophysio-logical technique in vitro. While imidacloprid levels of 0.01 and 0.1 μM had no significant effects (p＞0.05), treatments with higher concentrations (1, 10, 100, and 1000 μM) significantly reduced the action potential amplitude, area and latency when compared with those of untreated nerves (p＜0.05). These treatments caused the prolongation of the duration of action potential (p＜0.05). However, the antagonists α -bungarotoxin and mecamylamine reversed these effects (p＜0.05). Since both antagonists inhibited the effects of imidacloprid doses, it is possible that this insecticide displays its action to nicotinic acetylcholine receptor subtypes in the frog peripheral nervous system.