Variations in interpulse interval of double action potentials during propagation in single neurons

Authors

  • Edgar Villagran-Vargas,

    1. Membrane Biophysics Group, The Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
    Current affiliation:
    1. Departamento de Física, Universidad Autónoma del Estado de México, México
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  • Leonardo Rodríguez-Sosa,

    Corresponding author
    1. Departamento de Fisiología, Facultad de Medicina, Universidad Nacional Autónoma de México, Av. Universidad 3000, Ciudad Universitaria 04510, México, D.F., Mexico
    • Departamento de Fisiología, Facultad de Medicina, Universidad Nacional Autónoma de México, Av. Universidad 3000, Ciudad Universitaria 04510, México, D.F.. Mexico
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  • Reinhold Hustert,

    1. Department of Neurobiology, Institute for Zoology and Anthropology, University of Göttingen, Göttingen, Germany
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  • Andreas Blicher,

    1. Membrane Biophysics Group, The Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
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  • Katrine Laub,

    1. Membrane Biophysics Group, The Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
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  • Thomas Heimburg

    1. Membrane Biophysics Group, The Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
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Abstract

In this work, we analyzed the interpulse interval (IPI) of doublets and triplets in single neurons of three biological models. Pulse trains with two or three spikes originate from the process of sensory mechanotransduction in neurons of the locust femoral nerve, as well as through spontaneous activity both in the abdominal motor neurons and the caudal photoreceptor of the crayfish. We show that the IPI for successive low-frequency single action potentials, as recorded with two electrodes at two different points along a nerve axon, remains constant. On the other hand, IPI in doublets either remains constant, increases or decreases by up to about 3 ms as the pair propagates. When IPI increases, the succeeding pulse travels at a slower speed than the preceding one. When IPI is reduced, the succeeding pulse travels faster than the preceding one and may exceed the normal value for the specific neuron. In both cases, IPI increase and reduction, the speed of the preceding pulse differs slightly from the normal value, therefore the two pulses travel at different speeds in the same nerve axon. On the basis of our results, we may state that the effect of attraction or repulsion in doublets suggests a tendency of the spikes to reach a stable configuration. We strongly suggest that the change in IPI during spike propagation of doublets opens up a whole new realm of possibilities for neural coding and may have major implications for understanding information processing in nervous systems. Synapse, 2013. © 2012 Wiley Periodicals, Inc.

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