Abstract
The magnetic field outside an isolated axon is calculated using transmembrane potential data to specify the boundary conditions to a solution of Laplace's equation. It is shown that the contribution to the magnetic field from the current inside the membrane is two orders of magnitude larger than that from the external current. The contribution from current within the membrane is negligible. Comparisons are made between waveforms calculated for a crayfish lateral axon and those measured for a frog sciatic nerve. This calculation suggests that the magnetic field measured outside nerves can be used to determine their internal current without puncturing the nerve membrane.
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Selected References
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- Clark J. W., Jr, Greco E. C., Harman T. L. Experience with a Fourier method for determining the extracellular potential fields of excitable cells with cylindrical geometry. CRC Crit Rev Bioeng. 1978 Nov;3(1):1–22. [PubMed] [Google Scholar]
- Clark J., Plonsey R. A mathematical evaluation of the core conductor model. Biophys J. 1966 Jan;6(1):95–112. doi: 10.1016/S0006-3495(66)86642-0. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Clark J., Plonsey R. The extracellular potential field of the single active nerve fiber in a volume conductor. Biophys J. 1968 Jul;8(7):842–864. doi: 10.1016/S0006-3495(68)86524-5. [DOI] [PMC free article] [PubMed] [Google Scholar]
- WATANABE A., GRUNDFEST H. Impulse propagation at the septal and commissural junctions of crayfish lateral giant axons. J Gen Physiol. 1961 Nov;45:267–308. doi: 10.1085/jgp.45.2.267. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Wikswo J. P., Barach J. P., Freeman J. A. Magnetic field of a nerve impulse: first measurements. Science. 1980 Apr 4;208(4439):53–55. doi: 10.1126/science.7361105. [DOI] [PubMed] [Google Scholar]