Table 1.

Morphological parameters of simulated sparks

Condition	iRyR (pA/mM)	nRyR	Fmax/Fo	Δt(Fmax) (ms)	ΔF/Δt (ms−1)	FWHM (μm)	FDHM (ms)	n
Fig. 4	0.6	21	1.30 ± 0.03	14.3	0.15 ± 0.04	1.44 ± 0.03	19.6 ± 1.6	6
Square RyR cluster	0.6	16	1.04 ± 0.06	12.2	0.144 ± 0.017	1.40 ± 0.03	18.7 ± 2.0	17
Luminal gating	0.6	16	1.07 ± 0.02	12.9	0.141 ± 0.018	1.41 ± 0.03	19.0 ± 1.4	9
Sheep RyRs	0.6	16	1.07 ± 0.01	11.7	0.161 ± 0.007	1.42 ± 0.02	25.6 ± 2.1	3
Narrower dyad	0.6	16	0.86 ± 0.02	8	0.184 ± 0.022	1.07 ± 0.02	10.6 ± 0.9	4
nRYR varied	0.6	36	1.21 ± 0.01	12	0.175 ± 0.003	1.39 ± 0.02	18.8 ± 0.3	3
	0.6	16	1.04 ± 0.06	12.2	0.144 ± 0.017	1.40 ± 0.03	18.7 ± 2.0	17
	0.6	9	0.95 ± 0.02	13.7	0.113 ± 0.003	1.42 ± 0.03	23.5 ± 1.4	3
	0.6	4	0.68 ± 0.06	14.3	0.071 ± 0.003	1.38 ± 0.04	18.4 ± 2.0	6
	0.6	2	0.47 ± 0.05	9.7	0.069 ± 0.003	1.32 ± 0.03	14.8 ± 1.1	9
iRyR varied	0.6	16	1.04 ± 0.06	12.2	0.144 ± 0.017	1.40 ± 0.03	18.7 ± 2.0	17
	0.4	16	0.89 ± 0.07	13.2	0.108 ± 0.035	1.37 ± 0.05	16.5 ± 1.9	6
	0.35	16	0.87 ± 0.07	12.3	0.107 ± 0.025	1.35 ± 0.03	15.4 ± 1.1	7
	0.3	16	0.83 ± 0.07	13.2	0.098 ± 0.018	1.36 ± 0.02	15.9 ± 2.2	10
	0.25	16	0.74 ± 0.16	13.9	0.079 ± 0.023	1.37 ± 0.05	16.0 ± 2.5	10
	0.2	16	0.52 ± 0.27	10.3	0.067 ± 0.022	1.31 ± 0.07	13.7 ± 3.2	9
	0.15	16	0.38 ± 0.14	9.4	0.057 ± 0.007	1.30 ± 0.07	12.4 ± 3.2	12

First row is for the simulation depicted in Fig. 4. Subsequent rows show how spark properties change as various factors are altered, as indicated in the first column. i_RyR is the RyR single-channel Ca²⁺ current, n_RyR the number of RyRs in the simulated cluster, F_max/F_o the peak Ca²⁺ spark fluorescence change, Δt(F_max) the time to peak of the Ca²⁺ spark, ΔF/Δt the rate of rise of normalized fluorescence, FWHM the width of the spark at half-maximum amplitude, and FDHM the Ca²⁺ spark duration measured at half-maximum amplitude. Table gives mean ± SD of n simulations.