Figure 3. Results of simulations with the tetracube model using the four prototypical mechanisms.

The mechanisms were: “FI_fb” (fast-inactivated state is stabilized, with fast binding kinetics), “FI_sb” (fast-inactivated state is stabilized, with slow binding kinetics), “SI_fb” (slow-inactivated state is stabilized, with fast binding kinetics) and “SI_sb” (slow-inactivated state is stabilized, with slow binding kinetics). A, Concentration response curves. B, Effect of simulated “drugs” on “steady-state fast inactivation” (left panel) and “steady-state slow inactivation” (right panel) protocols. C, Effect of simulated “drugs” on the slow inactivation onset curve. D, Effect of simulated “drugs” on the recovery curve. E, Dependence of the effect of simulated “drugs” on the duration of the hyperpolarizing gap. The effect was quantified by calculating the areas between curves from the semilogarithmic plots. Box indicates data calculated from curves seen in Figure 3C.