Fig 4. Ephaptic field.

For one particular axon, randomly chosen as an example, central panel shows the time evolution of the extracellular potential (v_E) on the node of Ranvier lying closer to the electrode’s active pad for both simulations (blue for SNOEC, black for SEC), and left panel shows the time evolution of the transmembrane potential (v_m, same location and legend). Note in this panel how the EC produces an AP earlier than in SNOEC. Right panel: Time evolution of the endogenous fields ($v_E^{SEC}-v_E^{SNOEC}$) for all the axons (thin black lines) on the nodes lying closer to the active pad. Red lines indicate the mean of these fields (averaged for each time step, middle thick line) with their standard deviation (thin lines). The two black vertical lines indicate the start and finish of the pulse.