Intracortical and uniform E-field stimulation of a martinotti cell: A computational approach

Abstract

The aim of this thesis is the implementation of computational models for the investigationof the excitability of a Martinotti cell upon stimulation. The cell was modeled as a simple, stick neuron with a spherical cell body (soma) and additionally as a three-dimensional neuron with several branches, resembling a real geometry. The response of these models was tested to internal, external and uniform E-field stimulation. The latter was used for simulating transcranial magnetic stimulation.The axon terminal was the process with the smallest threshold amplitude during intracellular stimulation. Similarly, during extracellular cathodic stimulation, the less negative threshold amplitudes were observed above the axon terminal of the linear model and above a morphological discontinuity of the three-dimensional model. During transcranial magnetic stimulation the site of action potential initiation was the axon terminals or sites of termination in most of the cases. Spikes were not initiated at the soma or the axon initial segments for any orientation tested for both the linear and the three-dimensional models.