NERVE (version 2)

This program simulates the generation and propagation of the action potential by solving the Hodgkin and Huxley (HH) model for the space-clamped (membrane AP) or the partial differential equations of the simple core conductor cable with membrane characteristics based on the HH equations, for the propagated action potential (propagated AP).

PERFORMANCE HINTS

If you notice slow refreshing of the display, increase the Period.

IMPORTANT NOTE: When changing values with the keyboard, you must press ENTER to make them effective.

BUTTONS

-CONCENTRATIONS of ions on both sides of the membrane can be varied. The reversal potentials are computed for channels with non-ideal selectivity (ideal selectivity is selected in Axon Properties)

-AXON PROPERTIES can be modified. These include internal resistivity of the axon, radius, temperature and maximum Na, K and Leak conductances. In addition, selectivity may be changed from non-ideal to ideal.

-STIMULUS. Pulse amplitudes and durations can be varied along with the total time of computation.

-VARIABLES TO PLOT may be selected to plot along with the membrane voltage.

-PROPAGATED AP:

-click on V vs T for a plot of V versus time at three different points of the axon. The blue trace corresponds to the voltage read by the blue electrode whose position may be changed by dragging the electrode with the mouse along the axon.

-click on V vs X for a plot of the voltage profile along the axon as a function of time.

-click on CIRCUIT for a cable representation of two consecutive membrane patches during propagation

-MEMBRANE AP: Click to simulate.

-VOLTAGE CLAMP: Click to simulate.

-PERIOD: the period controls how often a simulation is initiated in the Membrane AP and in the Voltage clamp modes.

SHORTCUTS. Once in the membrane or propagated AP simulation modes, the following keys may be used:

F3- Start Simulation

F6- Axon properties

F7- Stimulus

F8- Concentrations

F9- Variables to plot

ESC- Closes the window in use

.