Faculty and Research
Faculty by Name
Harold Lecar
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Harold Lecar
Professor of the Graduate School Division of Neurobiology
Research Interests
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We study the membrane processes underlying excitation in the nervous system, particularly the gated ionic channels involved in electrical and chemical excitation.
Current Projects
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During the gating process, ionic channel proteins switch back and forth between ion-conducting and nonconducting configurations. These transitions can be observed in individual channels using the patch-electrode technique. Gated channels are involved in a great variety of membrane transduction processes including nerve impulse conduction, synaptic transmission, secretion, immune responses and sensory reception.
If we understand the gating properties of ion channels, we can construct mathematical models of the behavior of excitable cells. Stochastic excitation phenomena such as fluctuations in firing thresholds, firing frequencies, and the summation of random postsynaptic responses constitute the natural noise of the nervous system. The design of excitable cells—whether they function as oscillators, or encoders of sensory information, or controllers of secretion—is determined by the types and densities of the channel proteins in the cell membrane.
Selected Publications
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Biophysics of mechanotransduction. [H. Lecar and C. E. Morris (1993) In: Mechanoreception by the Vascular Wall, G. M. Rubanyi, ed., Futura Publishing Co. pp. 1-11]
Stochastic models for mechanical transduction. [F. Sachs and H. Lecar (1991) Biophys. J. 59, 1143-1145]
Molecular and Cell Biophysics. [R. Nossal and H. Lecar (1991) Addison Wesley Publishing Co.]
Ionic channels in the plasma membrane of Schizosaccharomyces pombe: Evidence from patch-clamp measurements. [H. Lecar (1990) Proc. Small Meeting on Yeast Transport and Energetics, Prague, Czechoslovakia]
Potassium-ion channels expressed by yeast PMA1 gene in Xenopus oocytes. [J. A. Ramirez, O. Baker, H. Lecar, J. Haber, and S. Harris (1990) Proc. 10th International Biophysics Conference, Vancouver, B.C.]
Trimeric gating of bacterial porins reconstituted in lipid bilayers. [V. Vacata, L. Gross, and H. Lecar (1990) Biophys. J. 56, 478a]
ATP-sensitive K+ channels in a plasma membrane H+ -ATPase mutant of the yeast Saccharomyces cerevisiae. [J. A. Ramirez, V. Vacata, J. H. McCusker, J.E. Haber, R.K. Mortimer, W. G. Owen, and H. Lecar (1989) Proc. Natl. Acad. Sci. USA 86, 7866-7870]
Single-channel currents and postsynaptic drug actions. [H. Lecar (1986) In: Ionic Channels in Cells and Model Systems, R. Latorre, ed., Plenum Press, pp. 17-35]
Gated ionic channels and the mechanism of excitability. [H. Lecar (1985) Federation Proc. 44, 2941-2943]
Single-channel currents activated by curare in cultured embryonic rat muscle. [C. E. Morris, B. S. Wong, M. B. Jackson, and H. Lecar (1983) J. Neurosci. 3, 2525-2531]
Successive openings of the same acetylcholine-receptor channel are correlated in their open times. [M. B. Jackson, B. S. Wong, C. E. Morris, H. Lecar and C. N. Christian (1983) Biophys. J. 42, 109-114]
Single cholinergic receptor channel currents in culture human muscle. [M. B. Jackson, H. Lecar, V. Askanas and W. King Engel (1983) J. Neurosci. 2, 1465-1473]
Single calcium-dependent potassium channels in clonal anterior pituitary cells. [B. S. Wong, H. Lecar, and M. Adler (1982) Biophys. J. 39, 313-317]
Single channel currents induced by complement in antibody-coated cell membranes. [M. B. Jackson, C. L. Stephens, and H. Lecar (1981) Proc. Natl. Acad. Sci. USA 78, 6421-6425]
Single postsynaptic channel currents in tissue cultured muscle. [M. B. Jackson and H. Lecar (1979) Nature 282, 863]
Last Updated 2003-09-02