Neurotransmitter Receptor Antagonism Inhibits the Sea Urchin Righting Response

Abstract

The deuterostome superphylum comprises the chordates, which includes all vertebrates, echinoderms (including sea urchins and sea stars), and hemichordates (acorn worms). Despite the close phylogenetic relationship between invertebrate echinoderms and vertebrates, the understanding of echinoderm neurobiology lags far behind that of many other invertebrate species. To investigate molecular components of echinoderm behavior, we used the righting response, in which an inverted sea urchin will use its tube feet and spines to right itself, as a behavioral assay. Using purple sea urchins (Strongylocentrotus purpuratus) we demonstrate that immersion in drug solution is a simple and effective drug administration route. Using the drug immersion procedure, we show that the sea urchin righting response is inhibited in a dose‐dependent manner by the nicotinic acetylcholine receptor antagonist hexamethonium and also affected by the GABAA receptor antagonist bicuculline. In addition, decreasing the concentration of extracellular Ca2+ also inhibited the righting response. These data start to elucidate the receptor systems involved the control of sea urchin motor activity.Support or Funding InformationFunding was provided by the University of the South Conduff Fund and the University of the South Kresge Fund.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.