Modifying the Hodgkin-Huxley model for high frequency AC stimulation

Prior studies have shown that a reversible nerve conduction block can be induced by applying a high frequency alternating current (HFAC) electrical stimulus at frequencies above approximately 3kHz. The potential clinical and electrophysiological applications of this technique have led to a series of modeling studies analyzing the physiological mechanism that generates a HFAC conduction block; however, many of these studies have been based on axon models that are perhaps not valid for HFAC electrical stimulation. We show that the Hodgkin-Huxley model does not accurately predict trends observed in HFAC conduction block experiments on unmyelinated. nerve fibers over a frequency range from 3kHz to 50kHz. Further, modifying the Hodgkin-Huxley model to incorporate a frequency-dependent membrane capacitance results in a significant change in the high frequency response of the model while still preserving the standard characteristics of action potential propagation.