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.
This is a preview of subscription content, access via your institution
Access options
Subscribe to this journal
Receive 51 print issues and online access
$199.00 per year
only $3.90 per issue
Buy this article
- Purchase on Springer Link
- Instant access to full article PDF
Prices may be subject to local taxes which are calculated during checkout
Similar content being viewed by others
References
Chandler, W. K. & Meves, H. J. Physiol., Lond. 180, 788–820 (1965).
Hille, B. J. gen. Physiol. 58, 599–619 (1971).
Swenson, R. P. & Armstrong, C. M. Nature 291, 427–429 (1981).
Hodgkin, A. L., Huxley, A. F. & Katz, B. J. Physiol., Lond. 116, 424–448 (1952).
Mathias, R. T., Levis, R. A. & Eisenberg, R. S. J. gen. Physiol. 76, 1–31 (1980).
Narahashi, T., Moore, J. W. & Scott, W. R. J. gen. Physiol 47, 965–974 (1964).
Shrager, P. J. gen. Physiol. 64, 666–690 (1974).
Starkus, J. G. & Shrager, P. Am. J. Physiol. 235, C238–C244 (1978).
Hodgkin, A. L. & Huxley, A. F. J. Physiol., Lond. 116, 473–496 (1952).
Sigworth, F. J. Physiol., Lond. 307, 131–142 (1980).
Salzberg, B. M., Bezanilla, F. & Davila, H. Biophys. J. 33, 90a (1981).
Hille, B. J. gen. Physiol. 66, 535–560 (1975).
Begenisich, T. & Busath, D. J. gen. Physiol. 77, 489–502 (1981).
Lo, M. V. C. & Shrager, P. Biophys. J. 35, 31–43 (1981).
Meves, H. & Pichon, Y. J. Physiol., Lond. 251, 60 (1975).
Yeh, J. Z., Oxford, G. S., Wu, C. H. & Narahashi, T. Biophys. J. 16, 77–81 (1976).
Bean, B., Shrager, P. & Goldstein, D. J. gen. Physiol. 77, 233–253 (1981).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Shrager, P., Lo, MV. Influence of ionic current on Na+ channel gating in crayfish giant axon. Nature 296, 450–452 (1982). https://doi.org/10.1038/296450a0
Received:
Accepted:
Issue Date:
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.