Table 2.

Summary of Spark Properties

	No. of
Condition	Events	Cells		Amplitude	Half width	FDHM	Rise time
					μm	ms	ms
Reference	5301	9	Mean	1.85	1.11	8.85	4.79
			SEM	0.12	0.05	0.23	0.35
Caffeine	4741	9	Mean	1.98	1.42	10.2	5.67
			SEM	0.09	0.05	0.67	0.36
Low Mg	4944	12	Mean	1.92	1.31	11.0	5.60
			SEM	0.08	0.04	0.29	0.28
High Mg	775	7	Mean	1.44	0.82	8.69	5.40
			SEM	0.15	0.02	0.46	0.29

All events detected with amplitude >0.6 were included. Mean, average of individual cell averages. Reference and caffeine entries are the same as in Table , and were both calculated in the same experiments. Low Mg, experiments in permeabilized fibers; High Mg, cells under voltage clamp, after equilibration with a 7 mM Mg²⁺ internal solution.