The signal synchronization function of myelin

TL;DR

This paper proposes a novel function of myelin as a signal synchronization device using electromagnetic induction, challenging the traditional insulating view and explaining specific ultrastructural features.

Contribution

It introduces the concept of myelin as an inductive element facilitating electromagnetic signal synchronization between axons.

Findings

Non-random ultrastructural features of myelin are observed.

Cytoplasmic channels may act as coiled inductors.

Myelin may promote electromagnetic signal synchronization.

Abstract

The myelinated axons are widely present in both central and peripheral nervous systems. Its unique compact spiraling structure poses significant challenges to understanding its biological functions and developmental mechanisms. Conventionally, myelin is considered as an insulating layer to achieve saltatory conduction for the enhancement of the neural signal speed, which serves as the foundation of neuroscience. However, this insulating hypothesis is inadequate to account for various experimental observations, especially the long unmyelinated tract observed in the cortex. We here show non-random distributions in three ultrastructural features of myelin: the non-random spiraling directions, the localization preferences of myelin outer tongues, and the radial components along boundaries between oppositely spiraled myelin sheaths. These phenomena are predicted by a novel concept of myelin biological function, which we propose as the signal synchronization function. Our findings demonstrate that cytoplasmic channels within myelin may act as coiled inductors, facilitating electromagnetic induction between adjacent myelin sheaths, and thereby promoting signal synchronization between axons. This, in turn, explains the non-random ultrastructural features observed. We believe these insights lay the foundation for a new understanding of myelin inductive function.