Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Letter
  • Published:

Release of endogenous excitatory amino acids from turtle photoreceptors

Abstract

RESPONSES to light are transmitted from photoreceptors to second-order retinal neurons by chemical synapses that may use an excitatory amino acid (EAA) as the neurotransmitter. This hypothesis is based primarily on the pharmacological actions of EAA agonists and antagonists on the membrane potentials and light responses of second-order neurons1,2. But the release of endogenous E A As, which is a critical criterion for the identification of EAAs as transmitters3, has not been demonstrated. Here we report the use of outside-out membrane patches excised from rat hippocampal neurons to detect the release of EAAs from synaptic terminals of isolated turtle photoreceptors. Electrical stimulation of or application of lanthanum chloride to photoreceptors induced an increase in the frequency of opening of 50-pS channels in the patches. These channels were identified as the class of glutamate-activated channels that are also gated by aspartate and NMDA (N-methyl-D-aspartate). In several photoreceptor–patch pairs, spontaneous channel activity was observed near the synaptic terminals. These results provide strong evidence to support the hypothesis that both rods and cones of the turtle use an EAA as their neurotransmitter.

This is a preview of subscription content, access via your institution

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Similar content being viewed by others

References

  1. Massey, S. C. & Redburn, D. A. Prog. Neurobiol. 28, 55–96 (1987).

    Article  CAS  Google Scholar 

  2. Miller, R. F. & Slaughter, M. M. Trends Neurosci. 9, 211–218 (1986).

    Article  CAS  Google Scholar 

  3. Patton, W. D. M. A. Rev. Physiol. 20, 231–270 (1958).

    Article  Google Scholar 

  4. Hume, R. I., Role, L. W. & Fischbach, G. D. Nature 305, 632–634 (1983).

    Article  ADS  CAS  Google Scholar 

  5. Young, S. H. & Poo, M. Nature 305, 634–636 (1983).

    Article  ADS  CAS  Google Scholar 

  6. Jahr, C. E. & Stevens, C. F. Nature 325, 522–525 (1987).

    Article  ADS  CAS  Google Scholar 

  7. Nowak, L., Bregestovski, P., Ascher, P., Herbet, A. & Prochiantz, A. Nature 307, 462–465 (1984).

    Article  ADS  CAS  Google Scholar 

  8. Cull-Candy, S. G. & Usowicz, M. M. Nature 325, 525–528 (1987).

    Article  ADS  CAS  Google Scholar 

  9. Johnson, J. W. & Ascher, P. Nature 325, 529–531 (1987).

    Article  ADS  CAS  Google Scholar 

  10. Maricq, A. V. & Korenbrot, J. I. Neuron 1, 503–515 (1988).

    Article  CAS  Google Scholar 

  11. Kaneko, A. & Shimazaki, H. Cold Spring Harbor Symp. quant. Biol. 40, 537–546 (1976).

    Article  CAS  Google Scholar 

  12. Meriney, S. D., Young, S. H. & Grinnell, A. D. Proc. natn. Acad. Sci. U.S.A. 86, 2098–2102 (1989).

    Article  ADS  CAS  Google Scholar 

  13. Heuser, J. & Miledi, R. Proc. R. Soc. B179, 247–260 (1971).

    ADS  Google Scholar 

  14. Westbrook, G. L. & Mayer, M. L. Nature 328, 640–643 (1987).

    Article  ADS  CAS  Google Scholar 

  15. Attwell, D., Borges, S., Wu, S. M. & Wilson, M. Nature 328, 522–524 (1987).

    Article  ADS  CAS  Google Scholar 

  16. Belgum, J. H. & Copenhagen, D. R. J. Physiol. 396, 225–245 (1987).

    Article  Google Scholar 

  17. Lam, D. Proc. natn. Acad. Sci. U.S.A. 69, 1987–1991 (1972).

    Article  ADS  CAS  Google Scholar 

  18. Gerschenfeld, H. M. & Piccolino, M. in The Neurosciences: Fourth Study Program (eds Schmitt, F. O. & Worden, F G.) 216–226 (MIT Press, Cambridge, Massachusetts, 1979).

    Google Scholar 

  19. Nishimurea, Y., Schwartz, M. L. & Rakic, P. Nature 320, 753–756 (1986).

    Article  ADS  Google Scholar 

  20. Kaneko, A. & Tachibana, M. Proc. natn. Acad. Sci. U.S.A. 85, 5315–5319 (1988).

    Article  ADS  Google Scholar 

  21. Ehinger, B., Ottersen, O. P., Storm-Mathesin, J. & Dowling, J. E. Proc. natn. Acad. Sci. U.S.A. 85, 8321–8325 (1988).

    Article  ADS  CAS  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Rights and permissions

Reprints and permissions

About this article

Cite this article

Copenhagen, D., Jahr, C. Release of endogenous excitatory amino acids from turtle photoreceptors. Nature 341, 536–539 (1989). https://doi.org/10.1038/341536a0

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI: https://doi.org/10.1038/341536a0

This article is cited by

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.

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing