Figure 4

Voltage-dependent properties of the Kv currents. A) Steady state activation and inactivation properties of the Kv currents (all data are mean ± SD). Black squares represent activation of the sustained KDR current (n = 6); gray symbols represent transient KA current’s activation (circles, n = 5) and inactivation (triangles, n = 4). The curves are the corresponding Boltzmann fits: KDR activation is a 1^st order Boltzmann with V₅₀ = -31 mV and slope = 12 mV. KA activation is a 2^nd order Boltzmann with V ₅₀  = -43 mV and slope = 8.4 mV. KA inactivation is a 1^st order Boltzmann with V ₅₀  = -85 mV and slope = -11 mV. B) Activation time constants of KDR (black squares, n = 8 to 14) and KA (gray circles, n = 5). KDR activation time constant was fitted with a bell-function τ_KDR = 1/(4·exp(-43*V) + 156·exp(43*V)) s, where V is voltage in volts. KA activation time constant was nearly voltage-independent and was thus set to constant 1.5 ms for the simulations. C) Time constant of the KA inactivation (n = 3 to 7). Bell function is τ _KA  = 1/(341 ·exp(44·V) +0.211·exp(-44·V)) s, where V is voltage in volts. Inset: the inactivation recovery protocol used for voltages below -80 mV.