Figure 5. Effects of Ca²⁺ channel blockers on I_AHP.

A, example traces recorded from female GnRH neurone are shown. The voltage protocol was the same as in Fig. 2A. Attenuations by nifedipine and the addition of GVIA, Aga-IVA and SNX-482 are shown. B, time course of the effects of blockers on the total charge of I_AHP. Blockers were applied as indicated by horizontal bars. C, the effects of blockers are collectively shown as percentages of the control. The data are from female neurones. The oestrous cycle stage was not determined in this experiment. The effect of each blocker was statistically significant at P < 0.01 (n = 7–11) in paired t test. D, combined presentation of the effects of Ca²⁺ channel blockers on both the Ca²⁺ current and I_AHP. The same data presented as those in Figs 1B and 5C were used. The percentage of Ni²⁺, Cd²⁺-sensitive component is shown for I_sAHP. The percentage blockade by each Ca²⁺ channel blocker was similar for the Ca²⁺ current and I_sAHP.