1. Neuroscience
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Ionic mechanisms underlying history-dependence of conduction delay in an unmyelinated axon

  1. Yang Zhang
  2. Dirk M Bucher
  3. Farzan Nadim  Is a corresponding author
  1. New Jersey Institute of Technology, United States
Research Article
  • Cited 6
  • Views 963
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Cite this article as: eLife 2017;6:e25382 doi: 10.7554/eLife.25382

Abstract

Axonal conduction velocity can change substantially during ongoing activity, thus modifying spike interval structures and, potentially, temporal coding. We used a biophysical model to unmask mechanisms underlying the history-dependence of conduction. The model replicates activity in the unmyelinated axon of the crustacean stomatogastric pyloric dilator neuron. At the timescale of a single burst, conduction delay has a non-monotonic relationship with instantaneous frequency, which depends on the gating rates of the fast voltage-gated Na+ current. At the slower timescale of minutes, the mean value and variability of conduction delay increase. These effects are due to hyperpolarization of the baseline membrane potential by the Na+/K+ pump, balanced by an h-current, both of which affect the gating of the Na+ current. We explore the mechanisms of history-dependence of conduction delay in axons and develop an empirical equation that accurately predicts this history-dependence, both in the model and in experimental measurements.

Article and author information

Author details

  1. Yang Zhang

    Mathematical Sciences, New Jersey Institute of Technology, Newark, United States
    Competing interests
    The authors declare that no competing interests exist.
  2. Dirk M Bucher

    Biological Sceicnes, New Jersey Institute of Technology, Newark, United States
    Competing interests
    The authors declare that no competing interests exist.
  3. Farzan Nadim

    Biological Sciences, New Jersey Institute of Technology, Newark, United States
    For correspondence
    farzan@njit.edu
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0003-4144-9042

Funding

National Institute of Neurological Disorders and Stroke (NS083319)

  • Dirk M Bucher
  • Farzan Nadim

National Institute of Mental Health (MH060505)

  • Farzan Nadim

National Institute of Neurological Disorders and Stroke (NS058825)

  • Dirk M Bucher

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.

Reviewing Editor

  1. Frances K Skinner, University Health Network, Canada

Publication history

  1. Received: January 23, 2017
  2. Accepted: July 6, 2017
  3. Accepted Manuscript published: July 10, 2017 (version 1)
  4. Version of Record published: July 20, 2017 (version 2)

Copyright

© 2017, Zhang 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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