Parameter exploration of staircase-shape extracellular stimulation for targeted stimulation of myelinated axon.

Spatio-temporal dynamics of a mathematical model of myelinated axon in response to staircase-shape extracellular electrical stimulation, which was developed for selective nerve stimulation, is investigated by the computer simulation. It is shown that the response is classified into four types: subthreshold response, cathodic excitation, anodal block and anodal break excitation. Based on the simulation results, simple diagrams representing the response characteristics of the axon are constructed as functions of stimulation parameters and distance between the axon and electrode. The diagram would be useful for determining simulation parameters for dynamic targeted stimulation of myelinated axon.