ArticleThe Journal of general physiology2000
Time course and Ca(2+) dependence of sensitivity modulation in cyclic GMP-gated currents of intact 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 17 papers.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
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
17 citing papers in PubMed.
- Article
- Multi-scale, numerical modeling of spatio-temporal signaling in cone phototransduction.PloS one · 2019Article
- EML1 (CNG-modulin) controls light sensitivity in darkness and under continuous illumination in zebrafish retinal cone photoreceptors.The Journal of neuroscience : the official journal of the Society for Neuroscience · 2013Article
- Speed, sensitivity, and stability of the light response in rod and cone photoreceptors: facts and models.Progress in retinal and eye research · 2012Review
- Origin and control of the dominant time constant of salamander cone photoreceptors.The Journal of general physiology · 2012Article
- CNG-modulin: a novel Ca-dependent modulator of ligand sensitivity in cone photoreceptor cGMP-gated ion channels.The Journal of neuroscience : the official journal of the Society for Neuroscience · 2012Article
- Photoreceptor signaling: supporting vision across a wide range of light intensities.The Journal of biological chemistry · 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
- Binding by asynchrony: the neuronal phase code.Frontiers in neuroscience · 2010Article
- Native cone photoreceptor cyclic nucleotide-gated channel is a heterotetrameric complex comprising both CNGA3 and CNGB3: a study using the cone-dominant retina of Nrl-/- mice.Journal of neurochemistry · 2008Article
- Light adaptation in salamander L-cone photoreceptors.The Journal of neuroscience : the official journal of the Society for Neuroscience · 2008Article
- The limit of photoreceptor sensitivity: molecular mechanisms of dark noise in retinal cones.The Journal of general physiology · 2005Article
- 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
- Multiple steps of phosphorylation of activated rhodopsin can account for the reproducibility of vertebrate rod single-photon responses.The Journal of general physiology · 2003Article
- Circadian phase-dependent modulation of cGMP-gated channels of cone photoreceptors by dopamine and D2 agonist.The Journal of neuroscience : the official journal of the Society for Neuroscience · 2003Article
- GTPase regulators and photoresponses in cones of the eastern chipmunk.The Journal of neuroscience : the official journal of the Society for Neuroscience · 2003Article
- Photoreceptor light adaptation. Untangling desensitization and sensitization.The Journal of general physiology · 2000Review
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
3 authors.
Funding
Abstract
We determined the Ca(2+) dependence and time course of the modulation of ligand sensitivity in cGMP-gated currents of intact cone photoreceptors. In electro-permeabilized single cones isolated from striped bass, we measured outer segment current amplitude as a function of cGMP or 8Br-cGMP concentrations in the presence of various Ca(2+) levels. The dependence of current amplitude on nucleotide concentration is well described by the Hill function with values of K(1/2), the ligand concentration that half-saturates current, that, in turn, depend on Ca(2+). K(1/2) increases as Ca(2+) rises, and this dependence is well described by a modified Michaelis-Menten function, indicating that modulation arises from the interaction of Ca(2+) with a single site without apparent cooperativity. (Ca)K(m), the Michaelis-Menten constant for Ca(2+) concentration is 857 +/- 68 nM for cGMP and 863 +/- 51 for 8Br-cGMP. In single cones under whole-cell voltage clamp, we simultaneously measured changes in membrane current and outer segment free Ca(2+) caused by sudden Ca(2+) sequestration attained by uncaging diazo-2. In the presence of constant 8Br-cGMP, 15 micro, Ca(2+) concentration decrease was complete within 50 ms and membrane conductance was enhanced 2.33 +/- 0.95-fold with a mean time to peak of 1.25 +/- 0.23 s. We developed a model that assumes channel modulation is a pseudo-first-order process kinetically limited by free Ca(2+). Based on the experimentally measured changes in Ca(2+) concentration, model simulations match experimental data well by assigning the pseudo-first-order time constant a mean value of 0.40 +/- 0.14 s. Thus, Ca(2+)-dependent ligand modulation occurs over the concentration range of the normal, dark-adapted cone. Its time course suggests that its functional effects are important in the recovery of the cone photoresponse to a flash of light and during the response to steps of light, when cones adapt.
Indexed as
Identifiers
What OpenQuestion holds
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.