TY - JOUR
T1 - Amplitude distribution of calcium sparks in confocal images
T2 - Theory and studies with an automatic detection method
AU - Cheng, Heping
AU - Song, Long Sheng
AU - Shirokova, Natalia
AU - González, Adom
AU - Lakatta, Edward G.
AU - Ríos, Eduardo
AU - Stern, Michael D.
N1 - Funding Information:
This work was supported by National Institutes of Health (NIH) intramural research programs (to H.C., E.G.L., and M.D.S.); by grants from the NIH and the Muscular Dystrophy Association (to E.R.); and an NIH grant (to N.S.). A.G. was the recipient of a Senior Fellowship from the American Heart Association of metropolitan Chicago.
PY - 1999
Y1 - 1999
N2 - Determination of the calcium spark amplitude distribution is of critical importance for understanding the nature of elementary calcium release events in striated muscle. In the present study we show, on general theoretical grounds, that calcium sparks, as observed in confocal line scan images, should have a nonmodal, monotonic decreasing amplitude distribution, regardless of whether the underlying events are stereotyped. To test this prediction we developed, implemented, and verified an automated computer algorithm for objective detection and measurement of calcium sparks in raw image data. When the sensitivity and reliability of the algorithm were set appropriately, we observed highly left-skewed or monotonic decreasing amplitude distributions in skeletal muscle cells and cardiomyocytes, confirming the theoretical predictions. The previously reported modal or Gaussian distributions of sparks detected by eye must therefore be the result of subjective detection bias against small amplitude events. In addition, we discuss possible situations when a modal distribution might be observed.
AB - Determination of the calcium spark amplitude distribution is of critical importance for understanding the nature of elementary calcium release events in striated muscle. In the present study we show, on general theoretical grounds, that calcium sparks, as observed in confocal line scan images, should have a nonmodal, monotonic decreasing amplitude distribution, regardless of whether the underlying events are stereotyped. To test this prediction we developed, implemented, and verified an automated computer algorithm for objective detection and measurement of calcium sparks in raw image data. When the sensitivity and reliability of the algorithm were set appropriately, we observed highly left-skewed or monotonic decreasing amplitude distributions in skeletal muscle cells and cardiomyocytes, confirming the theoretical predictions. The previously reported modal or Gaussian distributions of sparks detected by eye must therefore be the result of subjective detection bias against small amplitude events. In addition, we discuss possible situations when a modal distribution might be observed.
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U2 - 10.1016/S0006-3495(99)77229-2
DO - 10.1016/S0006-3495(99)77229-2
M3 - Article
C2 - 9929467
AN - SCOPUS:0033037673
SN - 0006-3495
VL - 76
SP - 606
EP - 617
JO - Biophysical journal
JF - Biophysical journal
IS - 2
ER -