Hodgkin and Huxley Equations

The Hodgkin and Huxley (HH) equations employed in NeuroLab have remained the reference standard description for neuronal activity for almost five decades. Over this period, simulations using the HH equations have been found to reproduce a wide variety of neuronal situations.

A.L. Hodgkin and A.F. Huxley described the following in their classic 1952 paper, A quantative description of membrane current and its application to conduction and excitation in nerve:

  • Their analysis of an extraordinary set of voltage clamp current records on squid axon
  • Their most unusual expressions for fitting the underlying processes whose amplitude changes and time courses are functions of voltage:
  • potassium channel conductance kinetics
  • sodium channel conductance kinetics
  • An electrical equivalent circuit for the membrane which incorporates the inherent membrane capacity and ionic channels
  • Their system of equations, which describe the dynamics of the squid axon membrane circuit elements and include the voltage-sensitive descriptions of the ionic channels
  • Their calculations, which reconstruct the action potential and a propagating impulse

    • Additional appendix files describe the work leading up to this classical work of Hodgkin and Huxley:

  • The development of ideas about the processes underlying the action potential
  • How two electrical tools allowed simplification of the mathematical complexities of the electrical equivalent circuit:
  • Marmont's space clamp
  • Cole's voltage clamp
  • Limitations of the voltage clamp methodology
  • Facets of Hodgkin and Huxley's experiments on which their analysis was based


    •   Sir Alan Hodgkin, 1949           Sir Andrew Huxley, 1974

    The Hodgkin and Huxley papers are reproduced here in PDF format by permission of the Journal of Physiology, Sir Andrew L. Huxley, Sir Bernard Katz, and the late Sir Alan Hodgkin's family.