This is the Hodgkin-Huxley model of neural firing. The details are taken from Keener and Sneyd. 

The main parameter of interest to vary is Iapp, the input current. For input currents greater than about 6 uA the neuron fires periodically.

Note that time is in units of milliseconds.

The response to a brief pulse of input current is illustrated by choosing the input file singlepulse.dat

The response to more sustained pulses of input current are illustrated by choosing the input file multipulse.dat. This simulation shows the transition from steady to oscillatory behaviour as the input current is raised. 