Influence of Sodium Ions on Transmitter Release


WHEN the amplitudes of end-plate potentials (e.p.p.s) are depressed at frog neuromuscular junctions by low concentrations of calcium, lowering the sodium ion concentration in the medium causes a large increase in e.p.p. amplitude which has been shown to be due to an increased output of transmitter1. In general, those changes in bathing media which increase the quantal content of e.p.p.s also increase the frequency of miniature end-plate potentials (m.e.p.p.s). It therefore seemed likely that m.e.p.p. frequency would be increased by reduction of the extracellular sodium ion concentration. This prediction was tested by measuring frequencies of spontaneous m.e.p.p.s at neuromuscular junctions in rat hemidiaphragms in vitro, before and after lowering the sodium ion concentration in the bathing solution.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.


  1. 1

    Birks, R. I., and Cohen, M. W., Symposium on Muscle (Academic Press, 1965). Kelly, J. S., Nature, 205, 296 (1965).

  2. 2

    Liley, A. W., J. Physiol., 132, 650 (1956).

  3. 3

    Liley, A. W., J. Physiol., 134, 427 (1956). Hubbard, J. I., J. Physiol., 159, 507 (1961).

  4. 4

    Del Castillo, J., and Katz, B., J. Physiol., 128, 396 (1955).

  5. 5

    Takeuchi, A., and Takeuchi, N., J. Gen. Physiol., 45, 1181 (1962).

  6. 6

    Lüttgau, H. C., and Niedergerke, R., J. Physiol., 143, 486 (1958).

Download references

Author information

Rights and permissions

Reprints and Permissions

About this article

Cite this article

GAGE, P., QUASTEL, D. Influence of Sodium Ions on Transmitter Release. Nature 206, 1047–1048 (1965) doi:10.1038/2061047a0

Download citation

Further reading


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.