PUBLICATION

Electrogenic hyperpolarization-elicited chloride transporter current in blue cones of zebrafish retinal slices

Authors
Fan, S.F. and Yazulla, S.
ID
ZDB-PUB-970423-2
Date
1997
Source
Journal of neurophysiology   77(3): 1447-1459 (Journal)
Registered Authors
Fan, Shih-fang, Yazulla, Stephen
Keywords
none
MeSH Terms
  • Animals
  • Chloride Channels/drug effects
  • Chloride Channels/physiology*
  • Electrophysiology
  • Enzyme Inhibitors/pharmacology
  • In Vitro Techniques
  • Ion Channel Gating/drug effects
  • Ion Channel Gating/physiology
  • Light
  • Ouabain/pharmacology
  • Potassium Channels/drug effects
  • Potassium Channels/physiology
  • Retina/cytology
  • Retina/drug effects
  • Retina/physiology*
  • Retinal Cone Photoreceptor Cells/drug effects
  • Retinal Cone Photoreceptor Cells/physiology*
  • Sodium-Potassium-Exchanging ATPase/antagonists & inhibitors
  • Tetraethylammonium Compounds/pharmacology
  • Ultraviolet Rays
  • Zebrafish/physiology*
PubMed
9084610 Full text @ J. Neurophysiol.
Abstract
Voltage-activated currents in blue cones of the retinal slice of zebrafish were characterized using whole cell recording techniques. Depolarizing-elicited currents were recorded: an outward tetraethylammonium (TEA)-sensitive K+ current (IKx), an outward Ca(2+)-activated Cl- current (ICl(Ca)), from which we inferred an inward Ca2+ current (ICa) as well as a hyperpolarizing-elicited nonselective inward cation current (Ih). In addition, hyperpolarizing steps elicited an outward current (Iout-h) in about one-third of the blue cones. Iout-h seems to be carried by inward transported Cl- because it was abolished by equimolar substitution of bath Cl- with acetate; equimolar substitution of Na+ with choline or TEA had no effect; it was not affected by Cl- channel blockers, anthracene-9-carboxylic acid, 4,4'-diisothiocyanostilbene-2.2'- disulfonic acid, N-phenylanthranilic acid (DPC), niflumic acid, and 4-acetamido-4'-isothiocyanostilbene-2,2'-disulfonic acid but was suppressed by Cl- transporter blockers acetalzolamide, bumetanide, N-ethylmaleimide, furosemide, and vanadate, and no reversal potential was found. In addition, this current was suppressed by ouabains but unrelated to their Na(+)-K(+)-ATPase inhibitory effect, was not suppressed by Co2+ or nifedipine, was not affected by the gap junction decoupler, 2-octanol, was increased by bath application of Cs+, presumably due to suppression of Ih, which was masked by Iout-h, and was suppressed by intensive light. Similar current also was found in the short cones and double cones. As Iout-h operates over the same voltage range, and with similar magnitude and time course as Ih, we suggest that Iout-h contributes to the modulation of the photoresponse of cones.
Genes / Markers
Figures
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Mutations / Transgenics
Human Disease / Model
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