title: Calcium ion, a putative intracellular messenger for light-adaptation in Limulus ventral photoreceptors.
abstract: Calcium ion fulfills several criteria for identifying an intracellular messenger for light-adaptation in Limulus photoreceptors. Direct injection of Ca++ mimicks two aspects of light-adaptation; sequestration of intracellular calcium tends to prevent light-adaptation; and light induces an increase in intracellular Ca++ as demonstrated by two independent techniques.
mesh_terms: D000222:Adaptation, Physiological; D000818:Animals; D001181:Arthropods / Q000502:physiology*; D002118:Calcium / Q000494:pharmacology / Q000502:physiology*; D004533:Egtazic Acid / Q000494:pharmacology; D006737:Horseshoe Crabs / Q000502:physiology*; D008027:Light; D009431:Neural Conduction / Q000187:drug effects; D010786:Photoreceptor Cells / Q000502:physiology*
chemical_list: D004533:Egtazic Acid; D002118:Calcium