Simulation of comparative thresholds for neural and cardiac tissue

It is well-known that neural tissue is more excitable than cardiac tissue. The source of the disparity appears to be less well-known. Membrane and fiber simulations, using the Chiu-Sweeney nerve model and the Ebihara-Johnson, Beeler-Reuter cardiac model, suggest that the myelinated structure-rather than membrane kinetics alone-is responsible for the greater excitability of neural tissue