. 2001 Dec 1;118(6):653–678. doi: 10.1085/jgp.118.6.653

Table 3.

Properties of Larger Sparks in Normal Ringer's and Elevated [K⁺] Ringer's

	1		2	3
R. pipiens
	Morphological parameter	Units	Normal Ringer's (N = 237)	13 mM [K⁺] Ringer's (N = 3,176)
	0–100% rise time	ms	3.70 ± 0.09	4.18 ± 0.03^a
	Peak amplitude	ΔF/F	1.06 ± 0.03	1.08 ± 0.01
	Decay time constant	ms	4.32 ± 0.13	4.60 ± 0.04
	FDHM	ms	5.37 ± 0.11	5.92 ± 0.04^a
	Late offset	ΔF/F	0.013 ± 0.002	0.013 ± 0.001
	FWHM	μm	0.95 ± 0.02	1.02 ± 0.01^a
	Mass	μm³	1.65 ± 0.14	1.94 ± 0.05
R. temporaria
	Morphological parameter	Units	Normal Ringer's (N = 69)	7.5–13 [K⁺] Ringer's (N = 132)
	0–100% rise time	ms	3.49 ± 0.15	4.10 ± 0.14^a
	Peak amplitude	ΔF/F	0.92 ± 0.02^b	0.84 ± 0.01^a,b
	Decay time constant	ms	4.92 ± 0.30^b	5.05 ± 0.23^b
	FDHM	ms	5.66 ± 0.23	6.18 ± 0.17^a
	Late offset	ΔF/F	0.014 ± 0.005	0.014 ± 0.005
	FWHM	μm	0.95 ± 0.04	0.99 ± 0.03
	Mass	μm³	1.28 ± 0.17	1.35 ± 0.13^a

Entries show mean ± SEM values for sparks with a fitted peak amplitude ≥0.7 ΔF/F. All data were obtained with a line scan period of 2.048 ms. ^aSignificant difference (at P < 0.05) between the mean values of columns 2 and 3. ^bSignificant difference between the corresponding mean values for R. temporaria and R. pipiens. The number of fibers were 15 (column 2) and 14 (column 3) for R. pipiens and 12 (column 2) and 4 (column 3) for R. temporaria (see Table and Table ). As described in the text, ΔF/F values in column 3 were corrected by the F′/F scaling procedure, with F′/F factors of 1.3, 1.2, and 1.1 (13, 10, and 7.5 mM [K⁺] Ringer's, respectively). For the sparks from R. pipiens in 13 mM [K⁺] Ringer's, the average value of spark amplitude from the 14 individual experiments ranged from 0.87 to 1.26 (mean ± SEM = 1.06 ± 0.03; N = 14). Temperature: 17–19°C for R. pipiens, 17–20°C for R. temporaria.