Table 1.

The amplitude and time course of evoked and spontaneous NTIs recorded from polymodal and cold-sensitive receptors

	n	Conduction velocity (m s−1)	+Peak(μV)	−Peak(μV)	+dV/dt max(normalized)	−dV/dt max(normalized)	Ratio
Polymodal
Evoked	36	1.1 ± 0.1	40 ± 3	−9 ± 1	2900 ± 127	−4119 ± 172	0.74 ± 0.05
Spontaneous	36	—	34 ± 2	−7 ± 1	2683 ± 120	−4186 ± 212	0.70 ± 0.06
Difference	—	—	5 ± 1**	−1 ± 1	211 ± 108*	65 ± 122	0.04 ± 0.02
Cold
Evoked	51	1.7 ± 0.1††	50 ± 4†	−8 ± 1	3260 ± 103††	−3449 ± 173††	0.99 ± 0.05
Spontaneous	51	—	47 ± 4††	−9 ± 1	3386 ± 107††	−3450 ± 179††	1.07 ± 0.05
Difference	—	—	3 ± 1**	1 ± 1	−146 ± 89*	−126 ± 59	−0.08 ± 0.03**

^*The maximum rates (V s⁻¹) of rise and fall were normalized with respect to NTI amplitude by dividing them by the peak-positive amplitude (see Methods). The ratio was calculated by dividing +dV/dt max by –dV/dt max. The difference was calculated by subtracting the values for the spontaneous NTIs from those for the evoked NTIs. The significance of the difference was calculated using one-sided, paired t tests (P < 0.05)

^**The maximum rates (V s⁻¹) of rise and fall were normalized with respect to NTI amplitude by dividing them by the peak-positive amplitude (see Methods). The ratio was calculated by dividing +dV/dt max by −dV/dt max. The difference was calculated by subtracting the values for the spontaneous NTIs from those for the evoked NTIs. The significance of the difference was calculated using one-sided, paired t tests (P < 0.01).

^†Statistical comparisons between the evoked or spontaneous NTIs from the polymodal and cold-sensitive receptors were made using unpaired t tests (P < 0.05)

^††Statistical comparisons between the evoked or spontaneous NTIs from the polymodal and cold-sensitive receptors were made using unpaired t tests (P < 0.01).