Table 1. Frequency of discrete events of Ca²⁺ release.

	Time		Space
Fibre	Rest	Pulse	Voltage insensitive	Voltage sensitive
0118c	2.38	1.34	5.59	0.73
0118e	1.77	1.84	7.13	0.64
0128o	0.99	3.09	2.63	0
0128p	4.30	7.87	8.99	1.44
0128v	5.68	7.35	2.13	0
0128w	0.37	0.22	1.71	0.08
0310a*	6.56	4.68	18.65	2.61
0310b*	4.68	6.37	7.28	0
Mean	3.34	4.09	9.15	0.69
s.e.m.	0.81	1.03	2.52	0.33

^>*RyR3 knockout cells. Listed are frequency densities (expressed as × 10^−aμm⁻¹ s⁻¹) of discrete events in image regions separated either in time or space. Time was separated into ‘pulse’, meaning while depolarizing pulse was applied, or ‘rest’, all other times. Space was separated into regions where depolarization produced release (which is always continuous), ‘voltage sensitive’, and regions without response to voltage, ‘voltage insensitive’.