ArticleThe Journal of general physiology2000
Fraction of the dark current carried by Ca(2+) through cGMP-gated ion channels of intact rod and cone photoreceptors.
Article in The Journal of general physiology, 2000. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 22 papers.
What it found
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
22 citing papers in PubMed, 58 citations in OpenAlex.
- PIP2 binding at allosteric site blocks activation in human rod CNG channels.Nature communications · 2026Article
- Structural basis of properties, mechanisms, and channelopathy of cyclic nucleotide-gated channels.Channels (Austin, Tex.) · 2023Review
- Analysis of dim-light responses in rod and cone photoreceptors with altered calcium kinetics.Journal of mathematical biology · 2023Article
- Biology, Pathobiology and Gene Therapy of CNG Channel-Related Retinopathies.Biomedicines · 2023Review
- cGMP Analogues with Opposing Actions on CNG Channels Selectively Modulate Rod or Cone Photoreceptor Function.Pharmaceutics · 2022Article
- Article
- Regulation of calcium homeostasis in the outer segments of rod and cone photoreceptors.Progress in retinal and eye research · 2018Review
- Retinal Cyclic Nucleotide-Gated Channels: From Pathophysiology to Therapy.International journal of molecular sciences · 2018Review
- Membrane guanylyl cyclase complexes shape the photoresponses of retinal rods and cones.Frontiers in molecular neuroscience · 2014Review
- Speed, sensitivity, and stability of the light response in rod and cone photoreceptors: facts and models.Progress in retinal and eye research · 2012Review
- Speed, adaptation, and stability of the response to light in cone photoreceptors: the functional role of Ca-dependent modulation of ligand sensitivity in cGMP-gated ion channels.The Journal of general physiology · 2012Article
- Spatiotemporal regulation of ATP and Ca2+ dynamics in vertebrate rod and cone ribbon synapses.Molecular vision · 2007Article
- Functional characterization and molecular cloning of the K+-dependent Na+/Ca2+ exchanger in intact retinal cone photoreceptors.The Journal of general physiology · 2007Article
- The limit of photoreceptor sensitivity: molecular mechanisms of dark noise in retinal cones.The Journal of general physiology · 2005Article
- Using total fluorescence increase (signal mass) to determine the Ca2+ current underlying localized Ca2+ events.The Journal of general physiology · 2004Article
- Longitudinal diffusion in retinal rod and cone outer segment cytoplasm: the consequence of cell structure.Biophysical journal · 2004Article
- In intact mammalian photoreceptors, Ca2+-dependent modulation of cGMP-gated ion channels is detectable in cones but not in rods.The Journal of general physiology · 2004Article
- GTPase regulators and photoresponses in cones of the eastern chipmunk.The Journal of neuroscience : the official journal of the Society for Neuroscience · 2003Article
- Calcium regulation in photoreceptors.Frontiers in bioscience : a journal and virtual library · 2002Review
- Visualization of Ca2+ entry through single stretch-activated cation channels.Proceedings of the National Academy of Sciences of the United States of America · 2002Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
6 authors at 3 institutions in 2 countries.
Funding
Abstract
The selectivity for Ca(2+) over Na(+), PCa/PNa, is higher in cGMP-gated (CNG) ion channels of retinal cone photoreceptors than in those of rods. To ascertain the physiological significance of this fact, we determined the fraction of the cyclic nucleotide-gated current specifically carried by Ca(2+) in intact rods and cones. We activated CNG channels by suddenly (<5 ms) increasing free 8Br-cGMP in the cytoplasm of rods or cones loaded with a caged ester of the cyclic nucleotide. Simultaneous with the uncaging flash, we measured the cyclic nucleotide-dependent changes in membrane current and fluorescence of the Ca(2+)-binding dye, Fura-2, also loaded into the cells. The ratio of changes in fura-2 fluorescence and the integral of the membrane current, under a restricted set of experimental conditions, is a direct measure of the fractional Ca(2+) flux. Under normal physiological salt concentrations, the fractional Ca(2+) flux is higher in CNG channels of cones than in those of rods, but it differs little among cones (or rods) of different species. Under normal physiological conditions and for membrane currents </=200 pA, the Ca(2+) fractional flux in single cones of striped bass was 33 +/- 2%, and 34 +/- 6% in catfish cones. Under comparable conditions, the Ca(2+) fractional flux in rod outer segments of tiger salamander was 21 +/- 1%, and 14 +/- 1% in catfish rods. Fractional Ca(2+) flux increases as extracellular Ca(2+) rises, with a dependence well described by the Michaelis-Menten equation. KCa, the concentration at which Ca(2+) fractional flux is 50% was 1.98 mM in bass cones and 4.96 mM in tiger salamander rods. Because Ca(2+) fractional flux is higher in cones than in rods, light flashes that generate equal photocurrents will cause a larger change in cytoplasmic Ca(2+) in cones than in rods.
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Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.