An analysis of the effect of nodal current on the stimulating potential field in relation to myelinated fibres

In the process of modeling the extracellular stimulation of nerve fibres, it is assumed that the potential outside the fibre is determined only by the stimulus current, electrode geometry and the extracellular medium, and is not distorted by the presence of the fibre. However, in the real situation, the extracellular potential field will vary as the membrane potential changes due to the fibre activities. In this study, a pilot model is developed to analyse the validity of this assumption under subthreshold conditions. A volume conductor approach is used to represent the extracellular medium. The pilot model integrates the volume conductor with a myelinated nerve fibre. A transient simulation is carried out and the results are compared with those determined without integrating the volume conductor approach. The results show that the presence of the fibre does not contribute considerable errors to the nerve fibre predictions