Sensitivity of the amplitude of the single muscle fibre action potential to microscopic volume conduction parameters

A microscopic model of volume conduction was applied to examine the sensitivity of the single muscle fibre action potential to variations in parameters of the source and of the volume conductor, such as conduction velocity, intracellular conductivity and intracellular volume fraction. The model results show that the sensitivity to the intracellular and extracellular conductivity depends on the distance from the source. The action potential amplitude is strongly influenced by the intracellular volume fraction. In this frequency-dependent model the amplitude is influenced by the conduction velocity to a smaller degree than predicted by previous studies, which use a noncapacitive homogeneous volume conductor model.