Letter | Published:

Soma potential of an interneurone controls transmitter release in a monosynaptic pathway in Aplysia


IN the molluscan nervous system, action potentials and synaptic potentials invade the soma so that its potential reflects intrinsically and extrinsically initiated electrical activity1. However, its functions related to the electrical activity of the neurone are unknown. Recently, it was shown that the soma potentials of arthropod interneurones controlled transmitter release on to motoneurones2,3. In Aplysia, soma potentials of some interneurones have been observed to have an effect on the size of post synaptic potentials (p.s.ps) in the cell with which they synapse; the possibility that p.s.ps were affected by changes in temporal properties of the spike induced by the soma potential4 or electronic coupling between cells9 was not excluded. We investigated this observation and report here that soma potentials of one interneurone regulate the release of transmitter, possibly by a direct effect on its terminals. Release can be sustained beyond the normal time course of the p.s.p. by prolonged depolarisation of the soma.

Access optionsAccess options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.


  1. 1

    Tauc, L. J. gen. Physiol. 45, 1077–1097 (1962).

  2. 2

    Maynard, D. & Walton, K. J. comp. Physiol. 97, 215–243 (1975).

  3. 3

    Burrows, M. & Siegler, M. Nature 262, 222–224 (1976).

  4. 4

    Shimahara, T. & Tauc, L. J. Physiol., Lond. 247, 299–319 (1975).

  5. 5

    Geduldig, D. & Junge, D. J. Physiol., Lond. 199, 347–365 (1968).

  6. 6

    Takeuchi, A. & Takeuchi, N. J. gen. Physiol. 45, 1181–1193 (1962).

  7. 7

    Katz, B. & Miledi, R. J. Physiol., Lond. 203, 459–487 (1969).

  8. 8

    Llinas, R., Steinberg, I. Z. & Walton, K. Proc. natn. Acad. Sci. U.S.A. 73, 2918–2922 (1976).

  9. 9

    Shimahara, T. & Peretz, B., in preparation.

  10. 10

    Kado, R. T. Science 182, 845–848 (1973).

  11. 11

    Miledi, R. Proc. R. Soc. Ser. B 183, 421–425 (1973).

  12. 12

    Graubard, K. Brain Res. 88, 325–332 (1975).

  13. 13

    Baker, P. F., Meves, H. & Ridgway, E. B. J. Physiol., Lond. 231, 527–548 (1973).

  14. 14

    Mullins, L. J. Fedn Proc. 35, 2583–2588 (1976).

  15. 15

    Tauc, L. & Gerschenfeld, H. Nature 192, 366–367 (1961).

Download references

Author information

Rights and permissions

Reprints and Permissions

About this article

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.