Calcium signalling in squid olfactory receptor neurons.
Isolated squid olfactory receptor neurons respond to dopamine and betaine with hyperpolarizing conductances. We used Ca(2+) imaging techniques to determine if changes in intracellular Ca(2+) were involved in transducing the hyperpolarizing odor responses. We found that dopamine activated release of Ca(2+) from intracellular stores while betaine did not change internal Ca(2+) concentrations. Application of 10 mM caffeine also released Ca(2+) from intracellular stores, suggesting the presence of ryanodine-like receptors. Depletion of intracellular stores with 100 microM thapsigargin revealed the presence of a Ca(2+) store depletion-activated Ca(2+) influx. The influx of Ca(2+) through the store-operated channel was reversibly blocked by 10 mM Cd(2+). Taken together, these data suggest a novel odor transduction system in squid olfactory receptor neurons involving Ca(2+) release from intracellular stores.
Piper
D R
DR
Department of Physiology, School of Medicine, University of Utah, Salt Lake City, UT 84108, USA.
Lucero
M T
MT
D000818:Animals; D001622:Betaine / Q000494:pharmacology; D002110:Caffeine / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism; D020013:Calcium Signaling; D002478:Cells, Cultured; D049832:Decapodiformes / Q000502:physiology*; D004298:Dopamine / Q000494:pharmacology; D007425:Intracellular Membranes / Q000378:metabolism; D009475:Neurons, Afferent / Q000378:metabolism / Q000502:physiology*; D009833:Olfactory Pathways / Q000502:physiology*; D019284:Thapsigargin / Q000494:pharmacology
D002110:Caffeine; D001622:Betaine; D019284:Thapsigargin; D002118:Calcium; D004298:Dopamine