Table 1.

Comparison of action potential discharge characteristics across populations of myelinated A- and Ah-type and unmyelinated C-type VGN for intact and ovariectomized female rats

Parameter	A Type		Ah Type		C Type
	Intact	OVX	Intact	OVX	Intact	OVX
RMP	−63.4±2.37	−61.5±1.69	−63.8±2.42	−62.0±1.17	−63.3±2.68	−61.6±2.77
APFT	−43.9±2.25	−41.6±2.93	−36.7±3.74	−35.6±2.79	−25.8±3.56	−27.5±4.56
APpeak	48.5±3.51	53.5±3.87	52.9±4.67	57.4±3.07	48.6±4.65	53.9±4.52
APD50	0.82±0.18	0.78±1.3	1.91±0.20	1.64±0.11*	2.69±0.64	2.50±0.44
AHPpeak	−66.4±1.59	−64.8±2.15	−67.3±1.99	−66.3±1.81	−67.9±2.08	−66.7±1.83
AHP80	20.0±13.4	18.1±4.26	58.4±25.5	74.3±24.8	85.9±31.5	80.7±41.0
UVAPD50	239±52	253±37	146±21	165±31	40.7±13.4	57.7±17.9
DVAPD50	−138±37	−153±45	−52.3±11.4	−63.2±9.8*	−38.3±14.3	−41.0±9.91
n	28	20	44	51	118	49

Average data are expressed as means ± SD for comparison of action potential (AP) discharge characteristics across populations of vagal afferent neurons (VGN) classified as myelinated A and Ah type and unmyelinated C type for both intact and ovariectomized (OVX) female rats. All APs were elicited by a 500-μs current pulse. RMP, resting membrane potential; APFT, AP firing threshold; AP_peak, peak of AP waveform; APD₅₀, AP duration at 50% peak-to-peak excursion of AP waveform; AHP_peak, peak of afterhyperpolarization; AHP₈₀, time required to reach 80% recovery to RMP from AHP_peak; UV_APD50 and DV_APD50, upstroke and downstroke velocities, respectively, measured at APD₅₀.

^*Significance (P < 0.05).