Dipolar extracellular potentials generated by axonal projections
- Institute of Theoretical Biology, Humboldt-Universität zu Berlin, Germany
- University of Maryland, United States
- RWTH Aachen, Germany
Abstract
Extracellular field potentials (EFPs) are an important source of information in neuroscience, but their physiological basis is in many cases still a matter of debate. Axonal sources are typically discounted in modeling and data analysis because their contributions are assumed to be negligible. Here, we established experimentally and theoretically that contributions of axons to EFPs can be significant. Modeling action potentials propagating along axons, we showed that EFPs were prominent in the presence of terminal zones where axons branch and terminate in close succession, as found in many brain regions. Our models predicted a dipolar far field and a polarity reversal at the center of the terminal zone. We confirmed these predictions using EFPs from the barn owl auditory brainstem where we recorded in nucleus laminaris using a multielectrode array. These results demonstrate that axonal terminal zones can produce EFPs with considerable amplitude and spatial reach.
Article and author information
Author details
Catherine Emily Carr
Funding
National Institute on Deafness and Other Communication Disorders (DC-00436)
- Catherine Emily Carr
German Ministry for Education and Research (01GQ1001A)
- Richard Kempter
Collaborative Research in Computational Neuroscience Program (01GQ1505A)
- Richard Kempter
National Science Foundation (1516357)
- Catherine Emily Carr
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Ethics
Animal experimentation: This study was performed in accordance with the recommendations in the Guide for the Care and Use of Laboratory Animals of the National Institutes of Health. All of the animals were handled according to approved institutional animal care and use committee (IACUC) protocols R-13-14 and R-16-11 of the University of Maryland. All experiments were non-recovery, with surgery performed under urethane anesthesia."
Copyright
© 2017, McColgan et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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Dipolar extracellular potentials generated by axonal projections
eLife 6:e26106.
https://doi.org/10.7554/eLife.26106
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