Letter | Published:

Influence of ionic current on Na+ channel gating in crayfish giant axon

Nature volume 296, pages 450452 (01 April 1982) | Download Citation

Subjects

Abstract

In studies of nerve excitation it is important to examine the possible interaction of voltage-sensitive gating mechanisms with components forming the pathway of ionic channels. There is evidence that permeant ions and gating are independent in Na+ channels1,2 of nerve fibres, but not in K+ channels3. Of interest in this and other studies of excitability is the determination of the physical basis for the resistance in series with the axon membrane (Rs)4. In an attempt to determine whether an appreciable Rs is associated with individual Na+ channels5, we have compared gating kinetics in conditions in which the ionic current through individual channels is varied while the total membrane current remains constant. The number of conducting Na+ channels, and thus their contribution to Rs, was lowered by addition of tetrodotoxin6. We report here that no more than 10% of the resistance in ‘series’ with activation gates is associated with the Na+ channel, and give some preliminary estimates for minimum distances between gates and ion-binding sites within the Na+ channel.

Access optionsAccess options

Rent or Buy article

Get time limited or full article access on ReadCube.

from$8.99

All prices are NET prices.

References

  1. 1.

    & J. Physiol., Lond. 180, 788–820 (1965).

  2. 2.

    J. gen. Physiol. 58, 599–619 (1971).

  3. 3.

    & Nature 291, 427–429 (1981).

  4. 4.

    , & J. Physiol., Lond. 116, 424–448 (1952).

  5. 5.

    , & J. gen. Physiol. 76, 1–31 (1980).

  6. 6.

    , & J. gen. Physiol 47, 965–974 (1964).

  7. 7.

    J. gen. Physiol. 64, 666–690 (1974).

  8. 8.

    & Am. J. Physiol. 235, C238–C244 (1978).

  9. 9.

    & J. Physiol., Lond. 116, 473–496 (1952).

  10. 10.

    J. Physiol., Lond. 307, 131–142 (1980).

  11. 11.

    , & Biophys. J. 33, 90a (1981).

  12. 12.

    J. gen. Physiol. 66, 535–560 (1975).

  13. 13.

    & J. gen. Physiol. 77, 489–502 (1981).

  14. 14.

    & Biophys. J. 35, 31–43 (1981).

  15. 15.

    & J. Physiol., Lond. 251, 60 (1975).

  16. 16.

    , , & Biophys. J. 16, 77–81 (1976).

  17. 17.

    , & J. gen. Physiol. 77, 233–253 (1981).

Download references

Author information

Affiliations

  1. Department of Physiology, University of Rochester Medical Center, Rochester, New York 14642, USA

    • Peter Shrager
    •  & Mei-Ven C. Lo

Authors

  1. Search for Peter Shrager in:

  2. Search for Mei-Ven C. Lo in:

About this article

Publication history

Received

Accepted

Published

DOI

https://doi.org/10.1038/296450a0

Comments

By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.