Letter | Published:

Fluorescently labelled Na+ channels are localized and immobilized to synapses of innervated muscle fibres

Naturevolume 321pages6366 (1986) | Download Citation

Subjects

Abstract

Segregation of voltage-dependent sodium channels to the hillock of motoneurones and nodes of Ranvier in myelinated axons is crucial for conduction of the nerve impulse1,2. Much less is known, however, about the distribution of voltage-dependent Na+ channels on muscle fibres. Recently, Beam et al.3 have shown that Na+ channels are concentrated near the neuromuscular junction. To determine the topography and mechanisms governing the distribution of voltage-dependent Na+ channels on muscle, microfluorimetry and fluorescence photobleach recovery (FPR) have now been used to measure the density and lateral mobility of fluorescently labelled Na+ channels on uninnervated and innervated muscle fibres. On uninnervated myotubes, Na+ channels are diffusely distributed and freely mobile, whereas after innervation the channels concentrate at neuronal contact sites. These channels are immobile and co-localize with acetylcholine receptors (AChRs). At extrajunctional regions the Na+ channel density is lower and the channels more mobile. The results suggest that the nerve induces Na+ channels to redistribute, immobilize and co-localize with AChRs at sites of neuronal contact.

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

    Coombs, J. S., Eccles, J. C. & Fatt, P. J. Physiol., Lond. 130, 291–325 (1955).

  2. 2

    Waxman, S. G. & Ritchie, J. M. Science 228, 1502–1507 (1985).

  3. 3

    Beam, K. G., Caldwell, J. H. & Campbell, J. T. Nature 313, 588–590 (1985).

  4. 4

    Angelides, K. J. & Nutter, T. J. J. biol. Chem. 258, 11948–11957 (1983).

  5. 5

    Darbon, H. & Angelides, K. J. J. biol. Chem. 259, 6074–6084 (1984).

  6. 6

    Angelides, K. J. Biochemistry 20, 4107–4118 (1981).

  7. 7

    Axelrod, D. A., Koppel, D. E., Schlessinger, J., Elson, E. L. & Webb, W. W. Biophys. J. 16, 1055–1069 (1976).

  8. 8

    Ravdin, P. & Axelrod, D. A. Analyt. Biochem. 58, 585–592 (1977).

  9. 9

    Role, L. W., Matossian, V. R., O'Brien, R. J. & Fischbach, G.-D. J. Neurosci. 5, 2197–2204 (1985).

  10. 10

    Roberts, W. M. & Almers, W. Biophys. J. 47, abstr. 189 (1985).

  11. 11

    Brockes, J. P. & Hall, Z. W. Biochemistry 14, 2100–2106 (1975).

  12. 12

    Cohen, S. & Barchi, R. L. Biochim. biophys. Acta 645, 253–261 (1981).

  13. 13

    Elmer, L. W., O'Brien, B., Nutter, T. J. & Angelides, K. J. Biochemistry 24, 8128–8137 (1985).

  14. 14

    Klausner, R. D., Kleinfeld, A. M., Hoover, R. L. & Karnovsky, M. J. biol. Chem. 255, 1286–1295 (1980).

  15. 15

    Stuhmer, W. & Almers, W. Proc. natn. Acad. Sci. U.S.A. 79, 946–950 (1983).

  16. 16

    Stya, M. & Axelrod, D. A. Proc. natn. Acad. Sci. U.S.A. 80, 449–453 (1983).

Download references

Author information

Author notes

    • Kimon J. Angelides

    Present address: Dept. of Physiology and Molecular Biophysics, Baylor College of Medicine, 1 Baylor Plaza, Houston, Texas, 77030, USA

Affiliations

  1. Department of Neuroscience and Center for Neurobiological Studies, University of Florida College of Medicine, Gainesville, Florida, 32610, USA

    • Kimon J. Angelides

Authors

  1. Search for Kimon J. Angelides in:

About this article

Publication history

Received

Accepted

Issue Date

DOI

https://doi.org/10.1038/321063a0

Further reading

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.