title: Propagation speed in myelinated nerve. II. Theoretical dependence on external Na and on temperature.
abstract: The Hodgkin-Huxley (H.H.) equations modified by Dodge for Rana pipiens myelinated nerve have been solved to determine how well the theory predicts the effects of changes of temperature and [Na(+)](0) on propagation. Conduction speed theta was found to have an approximately exponential dependence on temperature as was found experimentally, but the theoretical temperature coefficient (Q(10)) was low; 1.5 compared with the experimental finding of 2.95. theta was found to be a linear function of log ([Na(+)](0)) in contrast to the experimental finding of a square root dependence on [Na(+)](0). theta is 50% greater at one-fourth normal [Na(+)](0) than the theory predicts. The difference between the theoretical theta([Na(+)](0)) and the experimental theta([Na(+)](0)) is probably due to an imprecisely known variation of parameters and not to a fundamental inadequacy of the theory.
mesh_terms: D000200:Action Potentials; D000818:Animals; D001001:Anura; D001369:Axons / Q000502:physiology; D007700:Kinetics; D008433:Mathematics; D008564:Membrane Potentials; D008959:Models, Neurological; D009431:Neural Conduction / Q000187:drug effects; D011894:Rana pipiens; D012964:Sodium; D013696:Temperature
chemical_list: D012964:Sodium