Summary
The properties of single channels activated during spontaneous postsynaptic currents in small cultured rat hippocampal neurons were investigated in low-noise whole cell recordings. The technique of nonstationary fluctuation analysis, which has previously been applied to sodium currents, was modified so that fluctuations were measured around the least-squares scaled fit of the ensemble average to individual synaptic currents. This had the effect of separating channel gating fluctuations from the quantal fluctuations of scale from event to event. Single channel amplitude was estimated from the variance — current distribution, and the kinetics of channel gating fluctuations were studied. Channels involved in the non-N-methyl-D-aspartate (non-NMDA) phase of the excitatory glutamatergic postsynaptic current showed a single channel amplitude of 1.5 pS, while those in the NMD A phase had a conductance of 42 pS. The single channel conductance estimated for the inhibitory chloride synaptic current was 14 pS. In addition, NMDA phase channel openings could be resolved directly in the whole cell current against the low noise level afforded by the small cells. Single channel lifetime and amplitude distributions of the channels activated during the postsynaptic current were measured, and confirmed the accuracy of the fluctuation method.
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References
Ascher, P., and Nowak, L. (1988) Quisqualate and kainate-activated channels in mouse central neurones in culture. J. Physiol. (Lond.) 339, 227–246.
Ascher, P., Bregestovski, P., and Nowak, L. (1988) N-Methyl-D-aspartate activated channels of mouse central neurones in magnesium-free solutions. J. Physiol. (Lond.) 339, 207–226.
Bekkers, J. M., and Stevens, C. F. (1989) NMDA and non-NMDA receptors are colocalized at individual excitatory synapses in cultured rat hippocampus. Nature (Lond.) 341, 230–233.
Collingridge, G. L., and Lester, R. A. J. (1989) Excitatory amino acid receptors in the vertebrate central nervous system. Pharmacol. Rev. 40, 143–211.
Collingridge, G. L., Gage, P. W., and Robertson, B. (1984) Inhibitory postsynaptic currents in rat hippocampal CAI neurons. J. Physiol (Lond.) 356, 551–564.
Cull-Candy, S. G., and Usowicz, M. M. (1989) On the multiple-conductance single channels activated by excitatory amino acids in large cerebellar neurones of the rat. J. Physiol. (Lond.) 415, 555–582.
Cull-Candy, S. G., Howe, J. R., and Ogden, D. C. (1988) Noise and single channels activated by excitatory amino acids in rat cerebellar granule neurons. J. Physiol. (Lond.) 400, 189–222.
Ehrenstein, G., Lecar, H., and Nossal, R. (1970) The nature of the negative resistance in bimolecular lipid membranes containing excitability inducing material. J. Gen. Physiol. 55, 119–133.
Fishbach, G. D., and Schuetze, S. M. (1980) A post-natal decrease in acetylcholine channel open time at rat endplates. J. Physiol. (Lond.) 303, 125–137.
Forsythe, I. D. and Westbrook, G. L. (1988) Slow excitatory postsynaptic currents mediated by N-methyl-D-aspartate receptors on cultured mouse central neurones. J. Physiol. (Lond.) 396, 515–533.
Hamill, O. P., Marty, A., Neher, E., Sakmann, B., and Sigworth, F. J. (1981) Improved patch-clamp techniques for high-resolution recording from cells and cell-free membrane patches. Pflügers Arch. 391, 85–100.
Hille, B. (1984) Ionic Channels of Excitable Membranes, Sinauer Associated, Inc., Sunderland, MA.
Howe, J. R., Colquohoun, D., and Cull-Candy, S. G. (1988) On the kinetics of large-conductance glutamate-receptor ion channels in rat cerebellar granule neurons. Proc. R. Soc. Lond. B Biol. Sci. 223, 407–422.
Jahr, C. E., and Stevens. C. F. (1987) Glutamate activates multiple single channel conductances in hippocampal neurons. Nature (Lond.) 325, 522–525.
Lester, R. A. J., Clements, J. D., Westbrook, G. L., and Jahr, C. E. (1990) Channel kinetics determine the time course of NMDA receptor-mediated synaptic currents. Nature 346, 565–567.
Magleby, K. L., and Stevens, C. F. (1972) A quantitative description of end-plate currents. J. Physiol. (Lond.) 223, 173–197.
Marr, D., and Hildreth, E. (1980) Theory of edge detection. Proc. R. Soc. Lond. B Biol. Sci. 207, 187–217.
Neher, E., and Sakmann, B, (1976) Noise analysis of drug induced voltage clamp currents in denervated frog muscle fibres. J. Physiol. (Lond.) 258, 705–729.
Neher, E., and Stevens, C. F. (1977) Conductance fluctuations and ionic pores in membranes. Ann. Rev. Biophys. Bioeng. 6, 345–381.
Nelder, J. A., and Mead, R. (1965) A simplex method for function minimization. Comput. J. 7, 308–313.
Nowak, L., Bregestovski, P., Ascher, P., Herbet, A., and Prochiantz, A. (1984) Magnesium gates glutamate-activated channels in mouse central neurones. Nature (Lond.) 307, 462–465.
Ozawa, S., and Yuzaki, M. (1984) Patch-clamp studies of chloride channels activated by gamma-aminobutyric acid in cultured hippocampal neurons of the rat. Neurosci. Res. 1, 275–293.
Radian, R., Ottersen, O. P., Storm-Mathisen, J., Castel, M., and Kanner, B. I. (1990) Immunocytochemical localization of the GABA transporter in rat brain. J. Neurosci. 10, 1319–1330.
Segal, M., and Barker, J. L. (1984a) Rat hippocampal neurons in culture: properties of GABA-activated Cl- ion conductance J. Neurophysiol. (Bethesda) 51, 500–515.
Segal, M., and Barker, J. L. (1984b) Rat hippocampal neurons in culture: voltage clamp analysis of inhibitory synaptic connections. J. Neurophysiol (Bethesda) 52, 469–487.
Sigworth, F. J. (1977) Sodium channels in nerve apparently have two conductance states. Nature (Lond.) 270, 265–267.
Sigworth, F. J. (1980) The variance of sodium current fluctuations at the node of Ranvier. J. Physiol. (Lond.) 307, 97–129.
Steinbach, J. H. (1989) Structural and functional diversity in vertebrate skeletal muscle nicotinic acetylcholine receptors. Ann. Rev. Physiol. 51, 353–365.
Tang, C.-M., Dichter, M., and Morad, M. (1989) Quisqualate activates a rapidly inactivating high conductance ionic channel in hippocampal neurons. Science (Wash. D.C.) 243, 1474–1477.
Traynelis, S. F., Silver, R. A., and Cull-Candy, S. G. (1991) Nonstationary current-variance analysis of glutamate receptor-mediated EPSCs at the mossy fiber-granule cell synapse. Soc. Neurosci. 17, 534–535 (Abstract).
Werner, P., Voigt, M., Keinänen, K., Wisden, W., and Seeburg, P. (1991) Cloning of a putative high-affinity kainate receptor expressed predominantly in hippocampal CA3 cells. Nature 351, 742–744.
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© 1993 Birkhäuser Verlag Basel/Switzerland
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Robinson, H.P.C., Kawai, N. (1993). Single channel properties at the synaptic site. In: Pichon, Y. (eds) Comparative Molecular Neurobiology. EXS, vol 63. Birkhäuser Basel. https://doi.org/10.1007/978-3-0348-7265-2_13
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DOI: https://doi.org/10.1007/978-3-0348-7265-2_13
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