ODE Hodgkin-Huxley JOde Example

Eduardo Sontag's Hodgin-Huxley equations using JOde, for classroom use.
I is the applied current (for a more interesting problem, make it a function!)
Am, etc are the alphas; Bm, etc the betas
gm, etc are the conductances
Em, etc the reversal potentials
u is the voltage
C (capacitance) has been set to one

Student Assignment:

1. Try modifying the applied current so that you find the largest value for which only one voltage spike is produced (don't forget to "Submit All" each time that you change the current, so the program runs again!), and report at which value (approximately) the bifurcation occurs.
2. As the current is set respectively to the values 10, 20, 30, 40, 50, 60, the amplitude of the spikes remains roughly constant, but the number of spikes changes ("frequency modulation"); report how many spikes you see for each of these 6 values.
3. Now display only "n" and "h". Observe that n(t)+h(t) add up to a constant; report what is the value (approximately) of that constant.
4. Display also "m". Which changes fastest among n, m, and h?
5. Provide printouts to justify each of the above. Note that the print option allows you to save to a postscript file, in case that you prefer to email solutions. (If you have problems printing, see printing help. If all fails, do a "print screen"; most computers allow you to do that.)

View (General) Instructions on using the JOde Applet

Written by: Marek Rychlik (rychlik@u.arizona.edu)

Author's Home Page: http://alamos.math.arizona.edu