Abstract :
Electromagnetic numerical methods, such as the finite element method (FEM), admittance method (AM), or finite-difference time-domain (FDTD), often use models that are discretized based on the dielectric properties of included materials. When studying neural tissue, the values typically originate from measurements taken across bulk tissue. These are then used to describe the materials in the model as lumped circuital elements, converting each voxel into a homogeneous resistance. While this approach can provide a good estimate of the resistance of the tissue at macro-scales, it may be questionable when voxel resolutions down to 1–5 um are considered. At these voxel resolutions, each voxel may contain different sections of cell bodies, axons, dendritic regions, etc., each having different resistive properties. There is an inherent heterogeneity that is disregarded in previous homogeneous model approximations.
