Hodgkin-Huxley Neuron
Full 4-variable ODE model of the action potential
V (mV)
m (Na act)
h (Na inact)
n (K act)
Hodgkin-Huxley (1952 Nobel): C_m dV/dt = I - g_Na·m³h·(V-E_Na) - g_K·n⁴·(V-E_K) - g_L·(V-E_L).
Gating variables follow dx/dt = α_x(V)(1-x) - β_x(V)x. Action potentials fire when I_inj exceeds threshold ~7 μA/cm².