TABLE 1.

Steady-state activation and inactivation variables and time constants for voltage-dependent ionic channels

Ionic channels	m∞(V), V, in mV; τm(V), ms; h∞(V), V, in mV; τh(V), ms
Fast sodium (Na)	m∞Na = 1/{1 + exp[−(V + 43.8)/6]}; τmNa = τmNamax/cosh[(V + 43.8)/14],  τmNamax = 0.252. h∞Na = 1/{1 + exp[(V + 67.5)/10.8]}; τhNa = τhNamax/cosh[(V + 67.5)/12.8],  τhNamax = 8.456.
Persistent sodium (NaP)	m∞NaP = 1/{1 + exp[−(V + 47.1)/3.1]}; τmNaP = τmNaPmax/cosh[(V + 47.1)/6.2],  τmNaPmax = 1. h∞NaP = 1/{1 + exp[(V + 60)/9]}; τhNaP = τhNaPmax/[cosh(V + 60)/9],  τhNaPmax = 5,000.
Delayed rectifier potassium (K)	α∞K = 0.01·(V + 44)/{1 − exp[−(V + 44)/5]}; β∞K = 0.17·{exp[ − (V + 49)/40]}; m∞K = α∞K/(α∞K + β∞K); τmK = τmK max/(α∞K + β∞K), τmK max = 1.
High-voltage–activated calcium (CaL)	m∞CaL = 1/(1 + exp[−(V + 27.4)/5.7)]; τmCaL = 0.5. h∞CaL = 1/{1 + exp[(V + 52.4)/5.2]}; τhCaL = 18.
Calcium-dependent potassium [K(Ca2+)]	α∞K,Ca = 1.25 · 108 · [Ca]i2, β∞K,Ca = 2.5; m∞K,Ca = α∞K,Ca/(α∞K,Ca + β∞K,Ca); τ∞K,Ca = τmK,Camax · 1000/(α∞K,Ca + β∞K,Ca),  τmK max = 1–8.