Year: 2025
Type: preprint
Abstract: An old debate about the excitability of the neural myelin sheath, which was fought in Europe between the world wars of the last century, has been settled. Schwann cells are active players in excitation conduction! A study by G. David provides sufficient evidence for this.1 This means that the membranes of the myelin sheath are excitable, i.e., possess voltage-dependent cation channels. Na+ and K+ ion channels have already been identified and functionally analyzed in Schwann cell cultures.2 Because they share the same specifications as the ion channels of the axon membrane, it was assumed that the myelin sheath supplies the axon with ion channels.3 We will show that in selected former experimental studies, both the excitability and the generation of induced voltages of the Schwann membranes had already been documented—but not recognized as such. A new physical property, which inevitably arises as a consequence of membrane excitability, concerns the Lorentz forces that arise in the concentrically aligned Na+ ion channels during their synchronous depolarization. They generate a mechanical constriction wave that moves across the myelin sheath in the direction of excitation. This mechanical wave has already been documented for unmyelinated axons.4 Thus, the myelin sheaths not only bear the brunt of nerve conduction but also possess a pumping function that enables the rapid – already known – submembranous substrate transport of the axon. On this basis, models of the pathophysiology of Alzheimer’s disease and Parkinson’s disease can be developed, because both diseases obviously show a disturbance of intra-neural substrate transport.
Author: Wolfgang Herzberg
Institution: University of Applied Sciences Wedel
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: gold
OpenAlex ID: W4413812366