Action potential propagation and synchronisation in myelinated axons
Fig 2
Sketch of ion channel currents considered here, with representative profiles of membrane potential in nearby nodes.
After the membrane potential V reaches the threshold value Vthr, the current I is released. A: The instantaneous current is described by a delta-peak at t0, when the threshold value is reached. B: The simplest way to accommodate delays or refractoriness is to introduce a refractory period Δ, after which the instantaneous current is released. C: Exponential current with characteristic time scale τsp. D: A combination of exponential currents describes a realistic current profile.