Figure 12.

Effects of quinidine (0.3 mM) upon the sustained outward (I_{Steady state}) and the transient tail current (I_Tail). (A) Voltage pulse protocol used in all experiments. (B) Typical record showing currents recorded under standard conditions. (C) Currents subsequently recorded after ∼1 min exposure to 0.3 mM quinidine (Quin.). (D) Effects of quinidine upon the sustained outward current (I_{Steady state}) quantified as the mean current recorded during the final few ms of each voltage pulse. (E) Effects of quinidine on the peak tail current (I_Tail) quantified immediately after each test pulse. (F) Effects of quinidine upon the test voltage needed to induce half-maximal activation of tail. (G) Effects of quinidine upon the maximal value of I_Tail. All data are mean ± s.e.m. (n = 10); asterisks denote statistically significant effects of quindine (***P < 0.001, Student's t-test).