Limitations of approximate solutions for computing the extracellular potential of single fibers and bundle equivalents.
The mathematical description of the extracellular field generated by activity in an excitable fiber in an unbounded volume conductor will depend on assumptions made about the sources and the source-field relationship. This paper examines and compares the rigorous and conventional approximate solutions of Laplace's equation used to evaluate the extracellular potential of a single, cylindrical fiber. The single fiber is considered as both a prototypical element (such as a nerve or muscle fiber) and an elementary model of an entire multicellular preparation (e.g., nerve bundle or Purkinje strand). The effects of the fiber radius, the intracellular and extracellular conductivities, and the shape and extent of the source function (either the transmembrane potential or the intracellular potential) on the solutions are discussed. The results show that, in general, the approximate solutions are unsatisfactory for computing the surface extracellular potential when the single fiber is used to represent a large bundle (greater than 300 microns).
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Related Subject Headings
- Synaptic Transmission
- Nerve Fibers
- Muscles
- Models, Neurological
- Models, Biological
- Membrane Potentials
- Fourier Analysis
- Biomedical Engineering
- 4603 Computer vision and multimedia computation
- 4009 Electronics, sensors and digital hardware
Citation
Published In
DOI
EISSN
ISSN
Publication Date
Volume
Issue
Start / End Page
Related Subject Headings
- Synaptic Transmission
- Nerve Fibers
- Muscles
- Models, Neurological
- Models, Biological
- Membrane Potentials
- Fourier Analysis
- Biomedical Engineering
- 4603 Computer vision and multimedia computation
- 4009 Electronics, sensors and digital hardware