Fig. 2.
Responses of the KM model (left column) and the reduced model (right column) to different levels of prepulse hyperpolarization with a depolarizing current, I0, of 130 pA at t = 70 ms. For the KM model the amplitudes of the 50 ms hyperpolarizing currents are −100, −150 and −200 pA (a, 1–3), respectively. With increasingly stronger hyperpolarization the firing behavior switches from regular firing to pauser and from pauser to buildup. We apply similar 50ms-hyperpolarization-then-depolarization stimuli to our reduced KM-LIF model and confirm that KM-LIF behaves similarly. The amplitudes of hyperpolarizing current for the reduced model are −80, −147, −200 pA (b, 1–3). Because KM-LIF has no Ih-current less hyperpolarizing current is required to attain similar hyperpolarized V– values as in full model. The time courses (dashed) of the inactivation gating variable, hf, of the fast transient potassium current, IKif, show that hyperpolarization removes inactivation