Morris-Lescar Model of Membranes with Multiple Ion Channels

applied current

159

initial membrane voltage V(0)

-60

initial fraction of open channels w(0)

0.5

relaxation rate of w

0.04

passive leak

2

Application of various depolarizing currents to barnacle muscle fibers produces spikes or oscillations for some values of the applied current. The Morris–Lescar model, which is a simplified version of the Hodgkin–Huxley model, involves a fast-activating calcium current; a slow potassium current, which is coupled to the calcium current; and a passive leak. The nonlinear simultaneous differential equations display bifurcation corresponding to these modes of behavior for various values of the relevant parameters.