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Effect of intracellularly applied sodium ions on the dark voltage of isolated retinal rods

Published online by Cambridge University Press:  02 June 2009

Karl-Friedrich Schmidt ,
Gottfried N. Nöll  and
Christian Baumann
Karl-Friedrich Schmidt
Affiliation:
Physiologisches Institut, Justus-Liebig-Universität Giessen, Federal Republic of Germany
Gottfried N. Nöll
Affiliation:
Physiologisches Institut, Justus-Liebig-Universität Giessen, Federal Republic of Germany
Christian Baumann
Affiliation:
Physiologisches Institut, Justus-Liebig-Universität Giessen, Federal Republic of Germany
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Abstract

Isolated retinal rods of the frog consisting of the outer segment and the ellipsoid were patch-clamped and recorded in the whole-cell mode. The recording pipettes were filled with solutions of different composition in order to alter the cytoplasmic content of sodium, phosphate, and calcium ions, and guanine nucleotides. When a simple medium with potassium as the principal cation was used, the dark voltage slowly approached more negative values. This tendency of spontaneous hyperpolarization was reduced significantly when cGMP or GTP were present in the pipette medium. Sodium ions, on the other hand, clearly increased the speed of hyperpolarization. In the presence of sodium (20 mM), the stabilizing effect of GTP did not occur and that of cGMP was clearly diminished. Phosphate (20 mM) neutralized the sodium effect. High calcium levels (100 μM) did not measurably influence the time course of hyperpolarization. We conclude that the normal cytoplasmic sodium level in rods does not exceed 10 mM and that higher internal sodium concentrations interfere with the sodium–calcium exchange mechanism.

Keywords

FrogPhotoreceptorRetinal rodSodium ionsPatch clamp
Type
Research Articles
Information
Visual Neuroscience , Volume 4 , Issue 4 , April 1990 , pp. 331 - 336
Copyright
Copyright © Cambridge University Press 1990

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References

Fenwick, E.M., Marty, A. & Neher, E. (1982). A patch-clamp study of bovine chromaffin cells and of their sensitivity to acetylcholine. Journal of Physiology 331, 577–597.CrossRefGoogle ScholarPubMed
Fesenko, E.E., Kolesnikov, S.S. & Lyubarsky, A.L. (1985). Induction by cyclic GMP of cationic conductance in plasma membrane of retinal rod outer segment. Nature 313, 310–313.CrossRefGoogle ScholarPubMed
Hamill, O.P., Marty, A., Neher, E., Sakmann, B. & Sigworth, F. (1981). Improved patch-clamp techniques for high-resolution current recording from cells and cell-free membrane patches. Pflügers Archiv 391, 85–100.CrossRefGoogle ScholarPubMed
Haynes, L.W., Kay, A.R. & Yau, K.-W. (1986). Single cyclic GMP-activated channel activity in excised patches of rod outer segment membrane. Nature 321, 66–70.CrossRefGoogle ScholarPubMed
Hodgkin, A.L., McNaughton, P.A. & Nunn, B.J. (1987). Measurement of sodium-calcium exchange in salamander rods. Journal of Physiology 391, 347–370.CrossRefGoogle ScholarPubMed
Johnson, E.A. & Kootsey, J.M. (1985). A minimum mechanism for Na+-Ca2+ exchange: net and unidirectional Ca2+ fluxes as function of ion composition and membrane potential. Journal of Membrane Biology 86, 167–187.CrossRefGoogle Scholar
Koch, K.-W. & Stryer, L. (1988). Highly cooperative feedback control of retinal rod guanylate cyclase by calcium ions. Nature 334, 64–66.CrossRefGoogle ScholarPubMed
Marty, A. & Neher, E. (1983). Tight-seal whole-cell recording. In Single-Channel Recording, ed. Sakmann, B. & Neher, E., pp. 107–122. New York: Plenum Press.CrossRefGoogle Scholar
Nakatani, K. & Yau, K.-W. (1988). Calcium and magnesium fluxes across the plasma membrane of the toad rod outer segment. Journal of Physiology 395, 695–729.CrossRefGoogle ScholarPubMed
Owen, W.G. (1987). Ionic conductances in rod photoreceptors. Annual Review of Physiology 49, 743–764.CrossRefGoogle ScholarPubMed
Pugh, E.N. Jr., (1987). The nature and identity of the internal excitational transmitter of vertebrate phototransduction. Annual Review of Physiology 49, 715–741.CrossRefGoogle ScholarPubMed
Pusch, M. & Neher, E. (1988). Rates of diffusional exchange between small cells and a measuring patch pipette. Pflügers Archiv 411, 204–211.CrossRefGoogle Scholar
Schmidt, K.-F., Baumann, C. & Nöll, G. (1985). Electrical parameters of retinal rods measured with the patch-clamp technique. Verhandlungen der Deutschen Zoologischen Gesellschaft 78, 296.Google Scholar
Schmidt, K.-F., Baumann, C. & Nöll, G. (1986). Membrane currents and membrane voltages of retinal rods of Rana esculenta recorded with patch-clamp electrodes. Verhandlungen der Deutschen Zoologischen Gesellschaft 79, 235.Google Scholar
Schmidt, K.-F., Nöll, G. & Baumann, C. (1989). Effect of guanine nucleotides on the dark voltage of single frog rods. Visual Neuroscience 2, 101–108.CrossRefGoogle ScholarPubMed
Schnapf, J.L. (1983). Dependence of the single photon response on longitudinal position of absorption in toad rod outer segments. Journal of Physiology 343, 147–159.CrossRefGoogle ScholarPubMed
Somlyo, A.P. & Walz, B. (1985). Elemental distribution in Rana pipiens retinal rods: quantitative electron-probe analysis. Journal of Physiology 358, 183–195.CrossRefGoogle ScholarPubMed
Torre, V. (1982). The contribution of the electrogenic sodium–potassium pump to the electrical activity of toad rods. Journal of Physiology 333, 315–341.CrossRefGoogle Scholar
Yau, K.-W. & Nakatani, K. (1984). Electrogenic Na–Ca exchange in retinal rod outer segment. Nature 311, 661–663.CrossRefGoogle ScholarPubMed
Zimmerman, A.L. & Baylor, D.A. (1986). Cyclic GMP-sensitive conductance of retinal rods consists of aqueous pores. Nature 321,70–72.CrossRefGoogle ScholarPubMed