Steady-state membrane currents at the subthresholds for two cell types.

<p>(A) The individual steady-state membrane currents at the subthreshold potentials for each cell type. Type II steady-state K⁺ current (<i>I</i>_K,SS) has activated prior to spike threshold (gray region), whereas this current does not activate at the threshold potentials (blue region) in Type I neuron. The other two currents, i.e., Na⁺ current (<i>I</i>_Na) and leak current (<i>I</i>_Leak), have the same subthreshold property for two cell types. (B) The steady-state total membrane current <i>I</i>_SS at the subthreshold potentials, i.e., <i>I</i>_SS-<i>V</i> curve. The Type II <i>I</i>_SS is outward at the perithresholds which arises from the activation of outward K⁺ current prior to threshold. In contrary, the Type I <i>I</i>_SS is inward which is much smaller than Type II. The total current <i>I</i>_SS is computed as the sum of all individual currents, i.e., K⁺, Na⁺ and leak currents.