SHORT COMMUNICATION TWO DISTINCT RECEPTORS ARE ACTIVATED BY ARECOLINE ON COCKROACH SIXTH ABDOMINAL

During the last decade, extensive biochemical and electrophysiological studies have been performed to characterize the pharmacological properties of cholinergic receptors of insect neurone somata (Sattelle, 1985; Breer and Sattelle, 1987; Benson, 1992). Although most of these studies have been focused on the pharmacological characterization of the cell body nicotinic receptors (Lane et al. 1982; Harrow and Sattelle, 1983; David and Sattelle, 1984; Benson, 1992), evidence for a population of acetylcholine (ACh) receptors exhibiting muscarinic and ‘mixed ’ (nicotinic/muscarinic) properties has been reported on insect neurone somata (Benson and Neumann, 1987; Knipper and Breer, 1988; Benson