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Activation of metabotropic glutamate receptors decreases a high-threshold calcium current in spiking neurons of the Xenopus retina

Published online by Cambridge University Press:  02 June 2009

Abram Akopian
Affiliation:
Department of Ophthalmology, New York University Medical Center, New York
Paul Witkovsky
Affiliation:
Department of Ophthalmology, New York University Medical Center, New York Department of Physiology & Neuroscience, New York University Medical Center, New York

Abstract

Two types of spiking neuron were identified among acutely dissociated neurons from the Xenopus retina by their responses to a depolarizing current step: single spikers and multiple spikers. In culture, multiple spikers had perikaryal diameters >15 μm, whereas single spikers had smaller somata, 5—10 μm in diameter. Using a conventional whole-cell patch-clamp technique, both T- and L-type calcium currents were identified in multiply spiking cells whereas only an L-type current was present in singly spiking cells. The metabotropic glutamate receptor (mGluR) agonist trans-(1S-3R)-1-amino-1,3-cyclopentane-dicarboxylic acid (trans-ACPD) significantly decreased the L-type calcium current by 46 ± 3% (mean ± S.E.M.) in both types of cell but had only a minor effect on the T-type current in multiply spiking neurons. In the presence of 50 μm 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX), 100 μM quisqualate (a potent mGluR1/5 agonist) decreased the L-type calcium current by 47 ± 9% but had no effect on the T-type current. The selective mGluR4/6/7 agonist (±) 2-amino-4-phosphonobutyric acid (L-AP4, 100 μM), and the mGluR2/3 agonist (2S,3S,4S)-α-(carboxycyclopropyl)glycine (L-CCG1, 100μM) decreased the L-type calcium current by 12 ± 3% and 14 ± 2%, respectively. The inhibition of calcium current by trans-ACPD was reduced when the patch pipette contained the G-protein inhibitor, GDPβS. The presence of the G-protein activator GTPγS in the patch pipette irreversibly reduced the L-type calcium current, but was without effect on the T-type current. Heparin applied intracellularly significantly reduced the inhibitory effect of quisqualate, indicating an involvement of the inositol triphosphate (IP3) pathway in the mGluR-induced reduction of calcium current. Replacement of internal EGTA with BAPTA significantly reduced the inhibitory effect of quisqualate. In contrast, internal application of cAMP did not prevent an inhibition of calcium current by quisqualate. Thus, the mechanism by which calcium current is inhibited by mGluR seems not to involve an intracellular cAMP cascade. Our findings indicate that activation of mGluR1/5 results in the inhibition of a high-threshold calcium current. This process is mediated by the activation of a G-protein and is consistent with inhibition occurring by an lPrstimulated release of internal calcium.

Type
Research Articles
Copyright
Copyright © Cambridge University Press 1996

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References

Akopian, A. & Witkovsky, P. (1994 a). Modulation of high-threshold calcium current by metabotropic glutamate receptor in ganglion cells of Xenopus retina. Society for Neuroscience Abstracts 20, 1574.Google Scholar
Akopian, A. & Witkovsky, P. (1994 b). Modulation of transient outward potassium current by GTP, calcium and glutamate in horizontal cells of Xenopus retina. Journal of Neurophysiology 71, 16611671.CrossRefGoogle ScholarPubMed
Baskys, A. (1992). Metabotropic receptors and slow excitatory actions of glutamate agonists in the hippocampus. Trends in Neuroscience 15, 9296.CrossRefGoogle ScholarPubMed
Beech, D.J., Bernheim, L. & Hille, B. (1992). Pertussis toxin and voltage dependence distinguish multiple pathways modulating calcium channels of rat sympathetic neurons. Neuron 8, 97106.CrossRefGoogle ScholarPubMed
Bossu, J.-L., Fagni, L., Nooney, J.M., Bockaert, J. & Feltz, A. (1992). Metabotropic glutamate receptor stimulation increases calcium currents in rat cerebellar granule cells. Society for Neuroscience Abstracts 18, 1272.Google Scholar
Carbone, E. & Lux, H.D. (1984). A low voltage-activated fully inactivating Ca channel in vertebrate sensory neurones. Nature 310, 501502.CrossRefGoogle ScholarPubMed
Charpak, S., Gaehweiler, B.H., Do, K.Q. & Knoepfel, T. (1990). Potassium conductances in hippocampal neurons blocked by excitatory amino acid transmitters. Nature 347, 765767.CrossRefGoogle ScholarPubMed
Chavis, P., Shinozaki, H., Bockaert, J. & Fagni, L. (1994). The metabotropic glutamate receptor types 2/3 inhibit L-type calcium channels via a Pertussis toxin-sensitive G-protein in cultured cerebellar granule cells. Journal of Neuroscience 14, 70677076.CrossRefGoogle Scholar
Eckert, R. & Tillotson, D.L. (1981). Calcium mediated inactivation of the Ca conductance in caesium-loaded giant neurons of Aplysia californica. Journal of Physiology (London) 317, 265280.CrossRefGoogle Scholar
Ehinger, E., Ottersen, O.P., Storm-Mathiesen, J. & Dowling, J.E. (1988). Bipolar cells in the turtle retina are strongly immunoreac-tive for glutamate. Proceedings of the National Academy of Sciences of the U.S.A. 85, 83218325.CrossRefGoogle Scholar
Fox, A.P., Nowycky, M.C. & Tsien, R.W. (1987). Kinetic and pharmacological properties distinguishing three types of Ca currents in chick sensory neurons. Journal of Physiology (London) 394, 149172.CrossRefGoogle Scholar
Frank, T.M. & Fein, A. (1991). The role of the inositol phosphate cascade in visual excitation of invertebrate microvillar photoreceptors. Journal of General Physiology 97, 697723.CrossRefGoogle ScholarPubMed
Guenther, E., Schmid, S., Grantyn, R. & Zrenner, E. (1994). In vitro identification of retinal ganglion cells in culture without the need of dye labeling. Journal of Neuroscience Methods 51, 177181.CrossRefGoogle ScholarPubMed
Hagiwara, S. & Byerly, L. (1992). Calcium channel. Annual Review of Neuroscience 4, 69125.CrossRefGoogle Scholar
Hamill, O.P., Marty, A., Neher, E., Sakmann, B. & Sigworth, F.J. (1981). Improved patch clamp techniques for high-resolution current recording from cells and cell-free membrane patches. Pflugers Archive 391, 85100.CrossRefGoogle ScholarPubMed
Hay, M. & Kunze, D.L. (1994). Glutamate metabotropic receptor inhibition of voltage-gated calcium currents in visceral sensory neurons. Journal of Neurophysiology 72, 421430.CrossRefGoogle ScholarPubMed
Hayashi, Y., Tanabe, Y., Aramori, I., Masu, M., Shimamoto, K., Ohfune, Y. & Nakanishi, S. (1992). Agonist analysis of 2-(carboxy-cyclopropyl)glycine isomers for cloned metabotropic glutamate receptor subtypes expressed in Chinese hamster ovary cells. British Journal of Pharmacology 107, 539543.CrossRefGoogle ScholarPubMed
Hille, B. (1992). Ionic Channels of Excitable Membranes, 2nd edition. Sunderland, Massachusetts: Sinauer Assoc., Inc.Google Scholar
Karschin, A. & Lipton, S.A. (1989). Ca channels in solitary retinal ganglion cells from postnatal rat. Journal of Physiology (London) 418, 379396.CrossRefGoogle Scholar
Kolb, H. (1982). The morphology of the bipolar cells, amacrine cells and ganglion cells in the retina of the turtle Pseudemys scripta elegans. Philosophical Transactions of the Royal Society B (London) 298, 355393.Google ScholarPubMed
Lasater, E. & Witkovsky, P. (1990). Membrane currents of spiking cells isolated from turtle retina Journal of Comparative Physiology A 167, 1121.CrossRefGoogle ScholarPubMed
Lester, R.A. & Jahr, C.E. (1990). Quisqualate receptor-mediated depression of calcium currents in hippocampal neurons. Neuron 4, 741749.CrossRefGoogle ScholarPubMed
Liu, Y. & Lasater, E. (1994). Calcium currents in turtle retinal ganglion cells. I. The properties of T and L-type currents. Journal of Neurophysiology 71, 733742.CrossRefGoogle ScholarPubMed
Marc, R.E., Liu, W.L., Kalloniatis, M., Raiguel, S.F. & Van Haesen-Donck, E. (1990). Patterns of glutamate immunoreactivity in the goldfish retina. Journal of Neuroscience 10, 40064034.CrossRefGoogle ScholarPubMed
Mayer, M.L. & Westbrook, G.L. (1987). The physiology of excitatory amino acids in the vertebrate central nervous system. Progress in Neurobiology 28, 197276.CrossRefGoogle ScholarPubMed
Nakanishi, S. (1992). Molecular diversity of glutamate receptors and implications for brain function. Science 258, 597603.CrossRefGoogle ScholarPubMed
Nomura, A., Shigemoto, R., Nakamura, Y., Okamoto, N., Mizuno, N. & Nakanishi, S. (1994). Developmentally regulated postsynaptic localization of a metabotropic glutamate receptor in rat rod bipolar cells. Cell 77, 361369.CrossRefGoogle ScholarPubMed
Nowycky, M.C., Fox, A.P. & Tsien, R.W. (1985). Three types of neuronal calcium channel with different calcium agonist sensitivity. Nature (London) 316, 440443.CrossRefGoogle ScholarPubMed
Pin, J.P. & Duvoisin, R. (1995). Review: Neurotransmitter receptors, I. The metabotropic glutamate receptors: Structure and function. Neuropharmacology 34, 126.CrossRefGoogle Scholar
Sahara, Y. & Westbrook, G.L. (1993). Modulation of calcium currents by a metabotropic glutamate receptor involves fast and slow kinetic components in cultured hippocampal neurons. Journal of Neuroscience 13, 30413050.CrossRefGoogle ScholarPubMed
Sayer, R.G., Schwindt, P.C. & Crill, W.E. (1992). Metabotropic glutamate receptor-mediated suppression of L-type calcium current in acutely isolated neocortical neurons. Journal of Neurophysiology 68, 833842.CrossRefGoogle ScholarPubMed
Schoepp, D.D., Bockaert, J. & Sladeczek, F. (1990). Pharmacological and functional characteristics of metabotropic excitatory amino acid receptors. Trends in Pharmacological Science 11, 508515.CrossRefGoogle ScholarPubMed
Schoepp, D.D. & Conn, J. (1993). Metabotropic glutamate receptors in brain function and pathology. Trends in Pharmacological Science 14, 1320.CrossRefGoogle ScholarPubMed
Schoepp, D.D., Johnson, B.C., Salhoff, C.R., Wright, R.A., Golds-Worthy, J.S. & Baker, S.R. (1995). Second-messenger responses in brain slices to elucidate novel glutamate receptors. Journal of Neuroscience Methods 59, 105110.CrossRefGoogle ScholarPubMed
Seeburg, P.M. (1993). the TIPS/TINS lecture: The molecular biology of mammalian glutamate receptor channels. Trends in Pharmacological Science 14, 297303.CrossRefGoogle ScholarPubMed
Swartz, K.J. & Bean, B.P. (1992). Inhibition of calcium channels in rat CA3 pyramidal neurons by a metabotropic glutamate receptor. Journal of Neuroscience 12, 43584371.CrossRefGoogle ScholarPubMed
Tanabe, Y., Masu, M., Ishii, T., Shigemoto, R. & Nakanishi, S. (1992). A family of metabotropic glutamate receptors. Neuron 8, 169179.CrossRefGoogle ScholarPubMed
Trombley, P.Q. & Westbrook, G.L. (1992). L-AP4 inhibits calcium currents and synaptic transmission via G-protein-coupled glutamate receptor. Journal of Neuroscience 12, 20432050.CrossRefGoogle ScholarPubMed
Tsien, R.Y. (1980). New calcium indicators and buffers with high selectivity against magnesium and protons: Synthesis and properties of prototype structure. Biochemistry 18, 23962404.CrossRefGoogle Scholar
Tsien, R.W., Lipscombe, D., Madison, D.V., Bley, K.V. & Fox, A.P. (1988). Multiple types of neuronal calcium channels and their modulation. Trends in Neuroscience 11, 431437.CrossRefGoogle ScholarPubMed