Open Access Library Journal 2021, Volume 8, e7379 ISSN Online: 2333-9721 ISSN Print: 2333-9705 DOI: 10.4236/oalib.1107379 May 11, 2021 1 Open Access Library Journal Another Train Paradox: May the Myelin Be with You! Bernard Delalande 1 , Hirohisa Tamagawa 2 , Vladimir Matveev 3 1 NeuroDynamique.fr, La Verpilliere, France 2 Department of Mechanical Engineering, Faculty of Engineering, Gifu University, 1-1 Yanagido, Gifu, Japan 3 Laboratory of Cell Physiology, Institute of Cytology, Russian Academy of Sciences, St. Petersburg, Russia Abstract For more than 70 years, biologists and biophysicists have been trying to un- ravel the mystery surrounding the saltatory conduction of so-called myeli- nated neurons. This conduction is indeed very different and faster than for fibres “without” myelin. Many theories have been developed. Albert Einstein used the metaphor of the train to explain the theory of relativity. It is also possible to use a similar metaphor to better understand this transient func- tioning of the neuron: the transmission of the action potential in myelinated fibres. By studying the various theories that have been put forward and con- fronting them with physics, mathematics and microscopic anatomical obser- vations, it is possible to refute or confirm certain hypotheses. It is easy and simple, then, to demonstrate unequivocally that the action potential cannot, in any way, jump from node of Ranvier (noR) to node of Ranvier as has been assumed and taught until now. It is possible to describe that the neuron uses an elegant and very simple method to increase the speed of transmission of the neuronal message. It is also important to conclude that this increase in speed, contrary to common belief, has an energetic cost that is greater than expected and that is proportional to the speed and in perfect agreement with the laws of thermodynamics. Subject Areas Biophysics, Neuroscience Keywords Axon, Neuron, Saltatory Conduction, Action Potential Propagation, Hodgkin and Huxley Model How to cite this paper: Delalande, B., Ta- magawa, H. and Matveev, V. (2021) Another Train Paradox: May the Myelin Be with You! Open Access Library Journal, 8: e7379. https://doi.org/10.4236/oalib.1107379 Received: April 1, 2021 Accepted: May 8, 2021 Published: May 11, 2021 Copyright © 2021 by author(s) and Open Access Library Inc. This work is licensed under the Creative Commons Attribution International License (CC BY 4.0). http://creativecommons.org/licenses/by/4.0/ Open Access