alpha-values
\alpha_n(V) = \frac{0.02mV^{-1} (V + 45.7mV)}{1 - \exp(-0.1mV^{-1} (V + 45.7mV))}
\alpha_m(V) = \frac{0.38mV^{-1} (V + 29.7mV)}{1 - \exp(-0.1mV^{-1} (V + 29.7mV))}
\alpha_h(V) = 0.266 \exp(-0.05mV^{-1} (V + 48.0mV))
beta-values
\beta_n(V) = 0.25 \exp(-0.0125mV^{-1} (V + 55.7mV))
\beta_m(V) = 15.2 \exp(-0.0556mV^{-1} (V + 54.7mV))
\beta_h(V) = \frac{3.8}{1 + \exp(-0.1mV^{-1} (V + 18mV))}
time constants
\tau_n(V) = \frac{1.0ms}{\alpha_n(V) + \beta_n(V)}
\tau_m(V) = \frac{1.0ms}{\alpha_m(V) + \beta_m(V)}
\tau_h(V) = \frac{1.0ms}{\alpha_h(V) + \beta_h(V)}
\tau_a(V) = 0.3632ms + \frac{1.158ms}{1.0 + \exp(0.0497mV^{-1} (V + 55.96mV))}
\tau_b(V) = 1.24ms + \frac{2.678ms}{1.0 + \exp(0.0624mV^{-1} (V + 50.0mV))}
asymptotic values
a_\infty(V) = \left( \frac{0.0761 * \exp(0.0314mV^{-1} (V + 94.22mV))}{1 + \exp(0.0346mV^{-1} (V + 1.17mV))}) \right)^{1 / 3} ms
b_\infty(V) = \left(\frac{1}{1 + \exp(0.0688mV^{-1} (V + 53.3mV))} \right)^4 ms
n_\infty(V) = \alpha_n(V) \tau_n(V)
m_\infty(V) = \alpha_m(V) \tau_m(V)
h_\infty(V) = \alpha_h(V) \tau_h(V)
Suitable initial conditions
m(t=0) = 0.010
n(t=0) = 0.156
h(t=0) = 0.966
a(t=0) = 0.540
b(t=0) = 0.289
V(t=0) = -68.0 mV
Parameter
c_m = 0.1 \frac{\mu F}{mm^2}
\frac{I_e}{A} = 0.35 \frac{\mu A}{mm^2}
\bar{g}_L = 0.003 \frac{mS}{mm^2}
\bar{g}_{Na} = 1.2 \frac{mS}{mm^2}
\bar{g}_{K} = 0.2 \frac{mS}{mm^2}
\bar{g}_{A} = 0.477 \frac{mS}{mm^2}
E_L = -17.0 mV
E_{Na} = 55.0 mV
E_K = -72.0 mV
E_A = -75.0 mV
