Spatial organization of cardiac gap junctions can affect access resistance

Authors

  • Dr. James E. Hall,

    Corresponding author
    1. Department of Physiology and Biophysics, University of California Irvine, Irvine, California 92717
    • Department of Physiology and Biophysics, University of California Irvine, Irvine, CA 9271
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  • Robert G. Gourdie

    1. Department of Cell Biology and Anatomy, Cardiovascular Developmental Biology Center, Medical University of South Carolina, Charleston, South Carolina 29425
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Abstract

In the heart, gap junctions electrically couple myocytes together. Electron- and light-microscope-based analyses have revealed that cardiac gap junctions show a variety of organizational patterns. At the level of gap-junctional channel aggregates, freeze fracture has demonstrated diverse channel packing arrangements in the membranes of different myocardial tissues. Ultrastructural and immunohistochemical studies have shown variation and specialization in the 3-dimensional spatial distribution of gap junctional contacts between different types of myocardial cells. Here, we estimate the access resistance of various configurations of gap junctions using physical principles and explore how certain of these specializations in gap-junctional organization may influence access resistance, a potentially important determinant of electrical conductance between coupled myocardial cells. © 1995 Wiley-Liss, Inc.

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