Modeling the effect of an external electric field on the velocity of spike propagation in a nerve fiber.
The effect of an externally generated electric field on the propagation of action potentials is modeled, assuming the Hodgkin-Huxley equation for the voltage-dependent conductance of the membrane of a nerve fiber. With some simplifying assumptions, this conductance together with Maxwell's equations leads to the Hodgkin-Huxley differential equations for propagation, modified by a term proportional to the gradient of the externally generated electric field component along the nerve fiber. Computer solution of these equations shows the influence of an electric field gradient on propagation velocity. When the electric field oscillates, voltage spikes starting later along a given axon advance or lag relative to earlier spikes, so the time between spikes at the receiving end differs from the time between spike originations. The amount that a low-frequency electric field modulates pulse timing at the end of a fiber relative to that at the beginning is estimated under several conditions.
Myers
J M
JM
Gordon McKay Laboratory, Harvard University, Cambridge, Massachusetts 02138, USA.
D000200:Action Potentials; D055592:Biophysical Phenomena; D001703:Biophysics; D003198:Computer Simulation; D004560:Electricity; D006801:Humans; D008564:Membrane Potentials; D008959:Models, Neurological; D009412:Nerve Fibers / Q000502:physiology*