Table 3.

Fast AP properties

[HCO3−]o (mm)	0	26	0	26
XE 991 (10 μm)	−	−	+	+
Threshold (mV)	−40 ± 2	−38 ± 2*	−43 ± 1	−41 ± 1*
AP amplitude (mV)	75 ± 3	71 ± 3	70 ± 2	67 ± 3
Half-width (μs)	800 ± 33	858 ± 47	866 ± 55	878 ± 68
fAHP amplitude (mV)a	7.8 ± 0.5	8.4 ± 0.5	6.3 ± 1.4	6.1 ± 1.5
n	6		5

AP amplitude, half-width, and fAHP properties were unaffected by wash-in of [HCO₃⁻]_o or KCNQ channel block by XE 991 (p > 0.05 for HCO₃⁻ effect, XE 991 effect and interaction, two-way RM ANOVA). AP thresholds were ∼2 mV higher in 26 mM [HCO₃⁻]_o both with and without XE 991 (p = 0.04 for HCO₃⁻; effect and p > 0.05 for XE 991 effect and interaction, two-way RM ANOVA). Values are mean ± SEM.

^afAHP amplitude was measured relative to AP threshold.

*Indicates statistical significance, two-way RM ANOVA.