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Biological Cybernetics

, Volume 18, Issue 1, pp 49–60 | Cite as

Adaptation and accommodation in the squid axon

  • Jürgen F. Fohlmeister
Article

Abstract

Current clamp data of the squid axon indicate that there is a qualitative change in the adaptive response as the magnitude of the current step is increased. Large stimulus currents have a strong inhibitory effect on spike generation and on active responses in general. Such currents always lead to only one action-potential and to the elimination of post-spike subthreshold oscillation. In view of a direct connection between stimulus current and potassium current IK, the potassium channel of the Hodgkin-Huxley model is reinterpreted in a natural way such that the K+ conductance is directly dependent on IK in addition to a voltage dependence. The I-Kdependence seems to dominate whenever the stimulus current is greater than approximately 35 μA/cm2. For current ramps, and large current steps, such a current formulation leads to good agreement with the data.

Keywords

Potassium Channel Active Response Qualitative Change Direct Connection Current Formulation 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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References

  1. 1.
    Adelman, W., Fitzhough, R.: Solutions of the Hodgkin-Huxley equations modified for potassium accumulation in periaxonal space. Abstr. Soc. Neurosc. (1973)Google Scholar
  2. 2.
    Adelman, W. J., Palti, Y., Senft, J. P.: Potassium accumulation in a periaxonal space and its effect on the measurement of membrane potassium ion conductance. J. Membrane Biol. 13, 387–410 (1973)Google Scholar
  3. 3.
    Cole, K. S.: Membranes, ions, and impulses. Berkeley Calif.: Univ. of Calif. Press 1968Google Scholar
  4. 4.
    Cole, K. S., Antosiewicz, H. A., Rabinowitz, P.: Automatic computation of nerve excitation. J. Soc. Indust. appl. Math. 3, 153–172 (1955)Google Scholar
  5. 5.
    Connor, J. A., Stevens, C. F.: Prediction of repetitive firing behavior from voltage clamp data on an isolated neurone soma. J. Physiol. (Lond.) 213, 31–53 (1971)Google Scholar
  6. 6.
    Fitzhugh, R.: Mathematical models of threshold phenomena in the nerve membrane. Bull. Math. Biophys. 17, 257–278 (1955)Google Scholar
  7. 7.
    Fitzhugh, R.: Impulses and physiological states in theoretical models of nerve membrane. Biophys. J. 1, 445–466 (1961)Google Scholar
  8. 8.
    Fitzhugh, R.: Mathematical models of excitation and propagation in nerve. In: Schwan, H. P. (Ed.). Biological engineering New York: McGraw-Hill 1969Google Scholar
  9. 9.
    Fitzhugh, R., Antosiewicz, H. A.: Automatic computation of nerve excitation — detailed corrections and additions. J. Soc. Indust. appl. Math. 7, 447–458 (1959)Google Scholar
  10. 10.
    Fohlmeister, J.: A model for phasic and tonic repetitively firing neuronal encoders. Kybernetik 13, 104–112 (1973)Google Scholar
  11. 11.
    Frankenhaeuser, B.: Delayed currents in myelinated nerve fibers of Xenopus Laevis investigated with voltage clamp technique. J. Physiol. (Lond.) 160, 40–45 (1962)Google Scholar
  12. 12.
    Frankenhaeuser, B.: A quantitative description of potassium currents in myelinated nerve fibers of Xenopus Laevis. J. Physiol. (Lond.) 169, 424–430 (1963)Google Scholar
  13. 13.
    Frankenhaeuser, B., Vallbo, A. B., Accommodation in myelinated nerve fibres of Xenopus Laevis as computed on the basis of voltage clamp data. Acta physiol. scand. 63, 1–20 (1965)Google Scholar
  14. 14.
    Hagiwara, S., Oomura, Y.: The critical depolarization for the spike in the squid giant axon. Japan J. Physiol. 8, 234 (1958)Google Scholar
  15. 15.
    Hille, B.: A pharmacological analysis of the ionic channels of nerve. Thesis: The Rockefeller University (No. 68-9584). Ann Arbor Mich.: Univ. Microfilms Inc. 1967Google Scholar
  16. 16.
    Hodgkin, A. L., Huxley, A. F.: A quantitative description of membrane current and its application to conduction and excitation in nerve. J. Physiol. (Lond.) 117, 500 (1952)Google Scholar

Copyright information

© Springer-Verlag 1975

Authors and Affiliations

  • Jürgen F. Fohlmeister
    • 1
  1. 1.Laboratory of NeurophysiologyUniversity of MinnesotaMinneapolisUSA

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