Figure 13.

Effects of 4-AP (2 mM) upon the sustained outward current (I_{Steady state}) and the transient tail current (I_Tail). Data were recorded using a pulse protocol identical to that shown in Fig. 12. (A) Currents recorded under standard conditions. (B) Currents recorded after ∼1 min exposure to 2 mM 4-AP. (C) Relationships between I_{Steady state} and test potential (V_Test) quantified under control conditions and in the presence of 4-AP. (D) I_Tail–V_Test relationships quantified under control conditions and in the presence of 4-AP. (E)Effects of 4-AP upon the voltage required to induce half-maximal activation of I_Tail (V₅₀). (F) Effects of 4-AP upon the maximal magnitude of I_Tail. All data are mean ± s.e.m. (n = 8); asterisks denote statistically significant effects of 4-AP (***P < 0.001, Student's t-test).