title: [Biophysical foundations of the neuronal activity].
abstract: OBJECTIVE
  It is sought to expose in a simple but rigorous way the fundamental basis of the classical biophysics.
  
  
  METHODS
  I start from the basic properties of a simple system (two solutions separated by a semipermeable membrane) in order to analyze the process of development of differences of potential. It is analyzed with special interest the development of the Nernst and Nernst-Planck equations. Then it is studied how this difference potential can originate, with different ionic species, the resting potential (Goldman, Hodgkin and Katz model). The next step consists in to analyze how the action potential arises. To do this, it will be of capital importance the mathematical model developed by Hodgkin and Huxley in the fifties; for it will be analyzed it thoroughly. Finally, some properties of the ionic channels will be commented that symbolize the biological implementation of the previous model.
  
  
  CONCLUSIONS
  The fundamental property of the nervous system that constitutes its biological sense is the handling of the information in a quick and sure way. This information codes it basically in form of potentials and its changes. For it, it would be important for clinical neurophysiologists, neurologists, neurosurgeons and psychiatrists to understand the mechanisms that underlie into the behavior of the nervous system.
authors.affiliation: Servicio de Neurofisiología Clínica, Hospital Ramón y Cajal, Madrid, España. jpastor@hrc.insalud.es
authors.forename: J
authors.initials: J
authors.lastname: Pastor
mesh_terms: D000818:Animals; D055592:Biophysical Phenomena; D001703:Biophysics; D001921:Brain / Q000502:physiology*; D006801:Humans; D007473:Ion Channels / Q000378:metabolism; D008954:Models, Biological; D009474:Neurons / Q000502:physiology*
chemical_list: D007473:Ion Channels