On the relation between axial resistance and conductivity in linear cable models

In the classical core conductor model the intra- and extracellular media of an infinitely long nerve or muscle fiber in a volume conductor are represented by parallel axial resistances. Thus, volume conductor properties are neglected. In this paper a study is presented that relates the conductivity of the intra- or extracellular medium of the fiber to the axial resistance used in the core conductor model. Expressions for the axial resistances that are dependent on the spatial frequency of the membrane current source density are derived from a volume conductor approach.