Physical Mechanisms of Nerve Excitability
The major physical process underlying transmission of signals in the nervous system is the transient flow of ionic currents across cell membrane in response to various stimuli. All cells are bounded by selectively permeable membranes, which allow ion flow in at least two different ways. There is passive flow through ionic channels, and active “pumped” flow against electrochemical potential gradients, “fueled” by metabolic energy (ATP splitting). We will be concerned with current flow through specific channels which are activated during nerve excitation. Active transport is used to charge the cell batteries but is only of indirect importance in the signalling process.
KeywordsExcitable Cell Squid Giant Axon Nerve Membrane Recovery Variable Cable Structure
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- 1.Hodgkin, A. L. and Huxley, A. F. (1952). J. Physiol. 117, 500–544. “A quantitative description of membrane current and its application to conduction and excitation in nerve.”Google Scholar
- 2.Hodgkin, A. L. (1964) “The Conduction of the Nervous Impulse”. Liverpool U. Press, Liverpool.Google Scholar
- 3.Cole, K. S. (1968). “Membranes, Ions and Impulses”. University of California Press, Berkeley.Google Scholar
- 7.Hille, B. (1975). “Ionic selectivity of Na and K channels of nerve membranes.” In “Membranes: A series of advances”. G. Eisenman, ed. Marcel Dekker, Inc., N.Y.Google Scholar
- 8.Ehrenstein, G. (1976). “Ionic channels in nerve membranes.” Physics Today 29, No. 10.Google Scholar
- 9.Jack, J.J.B., Noble, D. and Tsien, R.W. (1975). “Electric Current Flow in Excitable Cells”. Clarendon Press, Oxford.Google Scholar
- 11.Adrian, R. H. and Peachey, L. D. (1973). “Reconstruction of the Action Potential of Frog Sartorius Muscle.” J. Physiol. 235, 103–131.Google Scholar
- 12.FitzHhugh, R. (1969). “Mathematical models of excitation and propagation in nerve.” In “Biological Engineering”, H. P. Schwann, Ed. McGraw-Hill, Inc., N.Y.Google Scholar
- 14.Cohen, H. (1976). “Mathematical Developments in Hodgkin-Huxley Theory and its approximations.” Lectures on Mathematics in the Life Sciences.Google Scholar
- 16.Keynes, R. D. (1975)’ “The ionic channels in excitable membranes.” In Energy Transformation in Biological Systems. Ciba Foundation Symposium 31, 191–203.Google Scholar
- 17.Mueller, P. and Rudin, D.O. (1969). “Translocators in Biomolecular Lipid Membranes.” Current Topics in Bioenergetics 3: 157.Google Scholar
- 18.Ehrenstein, G. and Lecar, H. (1977) “Electrically Gated ionic channels in lipid bilayers.” Quarterly Reviews of Biophysics 10 (In press).Google Scholar