Luminescence control in the brittlestar Amphipholis squamata: Effect of cholinergic drugs

Potassium chloride and cholinergic drugs were rested on isolated arms of Amphipholis squamata; potassium chloride triggered a monophasic light emission; acetylcholine (10(-3) M) induced a luminescent response characterized by multiple flashes. ACh luminescence was increased in the presence of the cholinesterase inhibitor, eserine. Nicotinic antagonists, tubocurarine and hexamethonium chloride, had no inhibitory effect on the luminescence; muscarinic antagonists, atropine and benzotropine mesylate inhibited Amphipholis luminescence. These results suggest that the luminescence in A. squamata is mediated through a muscarinic cholinergic system. Copyright (C) 1996 Elsevier Science Inc.