PHYSIOLOGY OF ELECTROTONIC JUNCTIONS *

A number of different kinds of electrical interactions between cells are known. This paper is concerned with the numerous instances where cells behave essentially as if they are part of the same core conductor, that is, they are "electrotonically coupled". In many of these cases a distinct morphological relationship between the coupled cells can be demonstrated. As discussed in the preceding paper (Pappas & Bennett, 1966), there are regions where the membranes of the coupled cells come together, occluding the extracellular space. The correlation between electrotonic coupling and regions of membrane fusion allows the inference that these regions are the sites of coupling between cells. Thus, they may be considered electrotonic junctions. In this paper, two idealized cells connected by a resistance and capacity will be taken as a model of an electrotonic junction. The properties of this model will first be explored, and then its relationship to real examples considered.

[1]  A. R. Martin,et al.  Dual mode of synaptic transmission in the avian ciliary ganglion , 1963, The Journal of physiology.

[2]  Y. Washizu.  Single spinal montoneurons excitable from two different antidromic pathways. , 1960, The Japanese journal of physiology.

[3]  M. Kuno.  Quantal components of excitatory synaptic potentials in spinal motoneurones , 1964, The Journal of physiology.

[4]  S. Weidmann,et al.  The electrical constants of Purkinje fibres , 1952, The Journal of physiology.

[5]  E. Furshpan,et al.  Two inhibitory mechanisms in the Mauthner neurons of goldfish. , 1963, Journal of neurophysiology.

[6]  Theodore H. Bullock,et al.  Modulation of Activity of One Neuron by Subthreshold Slow Potentials in Another in Lobster Cardiac Ganglion , 1960, The Journal of general physiology.

[7]  R. Barrnett,et al.  FINE STRUCTURE OF THE NERVOUS SYSTEM OF HYDRA. , 1965, American zoologist.

[8]  M V Bennett,et al.  SPECIALIZED JUNCTIONS INVOLVED IN ELECTRICAL TRANSMISSION BETWEEN NEURONS. * , 1966, Annals of the New York Academy of Sciences.

[9]  Excitability changes in dorsal roots produced by electrotonic effects from adjacent afferent activity. , 1951, The American journal of physiology.

[10]  R. L. Wood.  Intercellular Attachment in the Epithelium of Hydra As Revealed by Electron Microscopy , 1959, The Journal of biophysical and biochemical cytology.

[11]  T. Sano,et al.  “Unidirectional” Atrioventricular Conduction Studied by Microelectrodes , 1960, Circulation research.

[12]  W. Loewenstein,et al.  Intercellular Electrical Coupling at a Forming Membrane Junction in a Dividing Cell , 1964, Science.

[13]  B. Katz,et al.  The measurement of synaptic delay, and the time course of acetylcholine release at the neuromuscular junction , 1965, Proceedings of the Royal Society of London. Series B. Biological Sciences.

[14]  W. Rall.  Membrane potential transients and membrane time constant of motoneurons. , 1960, Experimental neurology.

[15]  M. V. Bennett,et al.  Physiology and ultrastructure of electrotonic junctions. IV. Medullary electromotor nuclei in gymnotid fish. , 1967, Journal of neurophysiology.

[16]  H. Persson,et al.  Electrophysiologic and pharmacological observations on trypsin-disintegrated embryonic chick hearts cultured in vitro. , 1957, Acta physiologica Scandinavica.

[17]  W. Crill,et al.  Effects of membrane current on transmembrane potentials of cultured chick embryo heart cells. , 1959, The American journal of physiology.

[18]  H. Gerschenfeld,et al.  IONIC MECHANISM ASSOCIATED WITH NON-CHOLINERGIC SYNAPTIC INHIBITION IN MOLLUSCAN NEURONS. , 1965, Journal of neurophysiology.

[19]  H. Grundfest,et al.  Impulse Propagation at the Septal and Commissural Junctions of Crayfish Lateral Giant Axons , 1961, The Journal of general physiology.

[20]  R. Eckert.  Electrical Interaction of Paired Ganglion Cells in the Leech , 1963, The Journal of general physiology.

[21]  Y. Fukami,et al.  A THIRD TYPE OF INHIBITION IN THE MAUTHNER CELL OF GOLDFISH. , 1963, Journal of neurophysiology.

[22]  Harry Grundfest,et al.  Electrophysiology of Supramedullary Neurons in Spheroides maculatus , 1959, The Journal of general physiology.

[23]  W. Loewenstein,et al.  Intercellular Communication: Renal, Urinary Bladder, Sensory, and Salivary Gland Cells , 1965, Science.

[24]  J. Eccles.  The Physiology of Synapses , 1964, Springer Berlin Heidelberg.

[25]  S. Hagiwara,et al.  Electrotonic transmission between two nerve cells in leech ganglion. , 1962, Journal of neurophysiology.

[26]  M. V. Bennett,et al.  Physiology and ultrastructure of electrotonic junctions. II. Spinal and medullary electromotor nuclei in mormyrid fish. , 1967, Journal of neurophysiology.

[27]  W. Loewenstein,et al.  STUDIES ON AN EPITHELIAL (GLAND) CELL JUNCTION. II. SURFACE STRUCTURE. , 1964 .

[28]  A. Burnett,et al.  THE NERVOUS SYSTEM OF HYDRA. II. CONTROL OF GROWTH AND REGENERATION BY NEUROSECRETORY CELLS. , 1964, The Journal of experimental zoology.

[29]  M. Locke.  THE STRUCTURE OF SEPTATE DESMOSOMES , 1965, The Journal of cell biology.

[30]  S. Hagiwara,et al.  Potential changes in syncytial neurons of lobster cardiac ganglion. , 1959, Journal of neurophysiology.

[31]  L. Goldman.  The effects of stretch on cable and spike parameters of single nerve fibres; some implications for the theory of impulse propagation , 1964, The Journal of physiology.

[32]  E. Furshpan.  "Electrical Transmission" at an Excitatory Synapse in a Vertebrate Brain , 1964, Science.

[33]  K. Hama.  Some observations on the fine structure of the giant fibers of the crayfishes (Cambarus virilus and Cambarus clarkii) with special reference to the submicroscopic organization of the synapses , 1961, The Anatomical record.

[34]  W. Freygang,et al.  EXTRACELLULAR POTENTIALS FROM SINGLE SPINAL MOTONEURONS , 1959, The Journal of general physiology.

[35]  C. Wiersma,et al.  Neurons of arthropods. , 1952, Cold Spring Harbor symposia on quantitative biology.

[36]  M. V. Bennett.  NERVOUS FUNCTION AT THE CELLULAR LEVEL. , 1964, Annual review of physiology.

[37]  D. Potter,et al.  Transmission at the giant motor synapses of the crayfish , 1959, The Journal of physiology.

[38]  M. V. Bennett,et al.  Physiology and ultrastructure of electrotonic junctions. I. Supramedullary neurons. , 1967, Journal of neurophysiology.

[39]  Werner R. Loewenstein,et al.  STUDIES ON AN EPITHELIAL (GLAND) CELL JUNCTION I. Modifications of Surface Membrane Permeability , 1964 .

[40]  G. Pilar,et al.  Transmission through the ciliary ganglion of the chick , 1963, The Journal of physiology.