The effect of GV-58, a calcium channel modifier, on synaptic transmission at the larval Drosophila and crayfish neuromuscular junctions

GV-58 is known to increase the opening time of the mammalian P-type calcium channel in presynaptic motor nerve terminals. GV-58 is suggested as a therapeutic agent for dampening the symptoms of amyotrophic lateral sclerosis. To further understand the mechanisms of GV-58 actions, the <i>Drosophila</i> and crayfish neuromuscular junctions were used as models. Their presynaptic calcium channels are a P-type based on pharmacology profiles. However, exposure of GV-58 (1mM) did not produce any consistent alteration in synaptic transmission in these two preparations. It is possible that the molecular structure of the P-type channels is different in the <i>Drosophila</i> and crayfish.