ArticleThe Journal of general physiology2000
The spark and its ember: separately gated local components of Ca(2+) release in skeletal muscle.
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 43 papers.
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Who cites it
43 citing papers in PubMed, 70 citations in OpenAlex.
- Elementary calcium release events in the skeletal muscle cells of the honey bee Apis mellifera.Scientific reports · 2021Article
- High Time Resolution Analysis of Voltage-Dependent and Voltage-Independent Calcium Sparks in Frog Skeletal Muscle Fibers.Frontiers in physiology · 2020Article
- Calcium-induced release of calcium in muscle: 50 years of work and the emerging consensus.The Journal of general physiology · 2018Review
- Excitation contraction uncoupling by high intracellular [CaJournal of muscle research and cell motility · 2016Article
- Long-Lasting Sparks: Multi-Metastability and Release Competition in the Calcium Release Unit Network.PLoS computational biology · 2016Article
- Raptor ablation in skeletal muscle decreases Cav1.1 expression and affects the function of the excitation-contraction coupling supramolecular complex.The Biochemical journal · 2015Article
- Life and death of a cardiac calcium spark.The Journal of general physiology · 2013Article
- Comparison of myoplasmic calcium movements during excitation-contraction coupling in frog twitch and mouse fast-twitch muscle fibers.The Journal of general physiology · 2013Article
- Isoproterenol increases the fraction of spark-dependent RyR-mediated leak in ventricular myocytes.Biophysical journal · 2013Article
- Detection of calcium sparks in intact and permeabilized skeletal muscle fibers.Methods in molecular biology (Clifton, N.J.) · 2012Article
- Quarky calcium release in the heart.Circulation research · 2011Article
- Ryanodol action on calcium sparks in ventricular myocytes.Pflugers Archiv : European journal of physiology · 2010Article
- Frog alpha- and beta-ryanodine receptors provide distinct intracellular Ca2+ signals in a myogenic cell line.PloS one · 2010Article
- Altered expression of triadin 95 causes parallel changes in localized Ca2+ release events and global Ca2+ signals in skeletal muscle cells in culture.The Journal of physiology · 2008Article
- Intracellular calcium release channels mediate their own countercurrent: the ryanodine receptor case study.Biophysical journal · 2008Article
- Charged surface area of maurocalcine determines its interaction with the skeletal ryanodine receptor.Biophysical journal · 2008Article
- Calcium-dependent inactivation terminates calcium release in skeletal muscle of amphibians.The Journal of general physiology · 2008Article
- Does a lack of RyR3 make mammalian skeletal muscle EC coupling a 'spark-less' affair?The Journal of physiology · 2008Article
- Simulation of Ca2+ movements within the sarcomere of fast-twitch mouse fibers stimulated by action potentials.The Journal of general physiology · 2007Article
- Skeletal and cardiac ryanodine receptors exhibit different responses to Ca2+ overload and luminal ca2+.Biophysical journal · 2007Article
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Authors and funding
6 authors at 3 institutions in 2 countries.
Funding
No grant is acknowledged in the PubMed record.
Abstract
Amplitude, spatial width, and rise time of Ca(2+) sparks were compared in frog fast-twitch muscle, in three conditions that alter activation of release channels by [Ca(2+)]. A total of approximately 17,000 sparks from 30 cells were evaluated. In cells under voltage clamp, caffeine (0.5 or 1 mM) increased average spark width by 28%, rise time by 18%, and amplitude by 7%. Increases in width were significant even among events of the same rise time. Spontaneous events recorded in permeabilized fibers with low internal [Mg(2+)] (0.4 mM), had width and rise times greater than in reference, and not significantly different than those in caffeine. The spark average in reference rides on a continuous fluorescence "ridge" and is continued by an "ember," a prolongation of width approximately 1 microm and amplitude <0.2, vanishing in approximately 100 ms. Ridge and ember were absent in caffeine and in permeabilized cells. Exposure of voltage-clamped cells to high internal [Mg(2+)] (7 mM) had effects opposite to caffeine, reducing spark width by 26% and amplitude by 27%. In high [Mg(2+)], the ember was visible in individual sparks as a prolongation of variable duration and amplitude up to 1.2. Based on simulations and calculation of Ca(2+) release flux from averaged sparks, the increase in spark width caused by caffeine was interpreted as evidence of an increase in radius of the release source-presumably by recruitment of additional channels. Conversely, spark narrowing suggests loss of contributing channels in high Mg(2+). Therefore, these changes in spark width at constant rise times are evidence of a multichannel origin of sparks. Because ridge and ember were reduced by promoters of Ca(2+)-dependent activation (caffeine, low [Mg(2+)]) and became more visible in the presence of its inhibitors, they are probably manifestations of Ca(2+) release directly operated by voltage sensors.
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