Table 2.

Electrophysiological properties of IB4+ and IB4− C-fiber neurons

Types	IB4	CV		Em		Action potential						Nav1.9		Nav1.8
Types	IB4	n	m/s	n	mV	n	Base (ms)	RT (ms)	FT (ms)	Ht (mV)	Over (mV)	n	% rel intens	n	% rel intens
All	+	24	0.39	13	57.9	12	6.5	2.1	4.01	77	21	13	71	12	46
	−	11	0.52^*	10	47.6^*	5	3^*	1.04^**	1.92^†	61	6.4	7	17^*	7	49
LTMs	−	2	0.48	2	47.6	2	1.4	0.67	0.72	52	4.5	1	19	1	31
Noci type	+	24	0.39	13	57.9	12	6.5	2.1	4.01	77	21	13	71	12	46
	−	9	0.59^*	8	47.9^†	3	3.5	1.35^*	2.18	79	29	6	17^*	6	50

Median values for IB4+ and IB4− C-fiber neurons for CV, Em, and AP variables. AP variables included base (AP duration at base), RT (rise time), FT (fall time), Ht (AP height), and Over (AP overshoot). The values for All IB4+ and for C-nociceptor-type IB4+ neurons are the same, because all IB4+ C-fiber neurons were nociceptor type. Ems were included only if they were more negative than or equal to −40 mV. AP variable values were from neurons with Em of at least −40 mV and an overshooting AP. Statistical tests were Mann–Whitney U tests between all IB4+ and all IB4− neurons (asterisks in All IB4− row) and between IB4+ and IB4− C-nociceptor-type neurons (asterisks in C-nociceptor type IB4− row).
↵*p < 0.05;
↵**p < 0.01;
↵^†p = 0.05–0.1. rel intens, Relative intensity. For distribution of values, see Fig. 5.