A Physical Perspective to the Inductive Function of Myelin—A Missing Piece of Neuroscience

Abstract

Starting from the inductance in neurons, two physical origins are discussed, which are the coil inductance of myelin and the piezoelectric effect of the cell membrane. The direct evidence of the coil inductance of myelin is the opposite spiraling phenomenon between adjacent myelin sheaths confirmed by previous studies. As for the piezoelectric effect of the cell membrane, which has been well-known in physics, the direct evidence is the mechanical wave accompany with action potential. Therefore, a more complete physical nature of neural signals is provided. In conventional neuroscience, the neural signal is a pure electrical signal. In our new theory, the neural signal is an energy pulse containing electrical, magnetic, and mechanical components. Such a physical understanding of the neural signal and neural systems significantly improve the knowledge of the neurons. On the one hand, we achieve a corrected neural circuit of an inductor-capacitor-capacitor (LCC) form, whose frequency response and electrical characteristics have been validated by previous studies and the modeling fitting of artifacts in our experiments. On the other hand, a number of phenomena observed in neural experiments are explained. In particular, they are the mechanism of magnetic nerve stimulations and ultrasound nerve stimulations, the MRI image contrast issue and Anode Break Excitation. At last, the biological function of myelin is summarized. It is to provide inductance in the process of neural signal, which can enhance the signal speed in peripheral nervous systems and provide frequency modulation function in central nervous systems.

A Frequency Domain Analysis of the Excitability and Bifurcations of the FitzHugh–Nagumo Neuron Model

“…Hodgkin explains very clearly in his biography 61 that “the inductance is mainly due to the delayed increase in potassium conductance which can make membrane current lag behind voltage provided the internal potential is positive to the potassium equilibrium potential.” This interpretation of the inductor was supported by later measurements. 62 However, some present discussions 63 of the inductor still aim to find in neurons a magnetic coil or a piezoelectric effect. These physical properties are not needed because even minimal dynamical models generate the inductor as explained above.…”

“…This interpretation of the inductor was supported by later measurements. 62 However, some present discussions 63 of the inductor still aim to find in neurons a magnetic coil or a piezoelectric effect. These physical properties are not needed because even minimal dynamical models generate the inductor as explained above.…”

A physical perspective to understand myelin. I. A physical answer to Peter’s quadrant mystery

“…But the electric field can easily build the logical connection between the positions of inner and outer tongues. Another successful case is the explanation of the non-random spiraling directions between neighboring myelin sheaths by the electromagnetic field ( Wang et al, 2021 ). It is known that on the same axon, if one myelin sheath spiraling direction, from inner tongue to outer tongue, is clockwise, then the neighboring myelin sheath will have the opposite spiraling direction, which is anti-clockwise ( Uzman and Nogueira-Graf, 1957 ).…”

“…For example, a coil inductor model of the spiraling structure was used to understand the unique spiraling directions between adjacent myelin sheaths. ( Wang et al, 2021 ) To achieve a positive mutual inductance, the neighboring myelin on the same axon shall have opposite spiraling directions, while the neighboring myelin on the adjacent axons shall have the same spiraling direction. This simulation has been confirmed by SEM (scanning electron microscope) observations ( Waxman and Swadlow, 1976 ).…”

A physical perspective to understand myelin II: The physical origin of myelin development

“…Thus, a study from a physical perspective can provide a substantial body of new knowledge yet to be discovered. In our previous study, the non-random spiraling phenomenon and the same quadrant phenomenon were explained from the perspective of the electromagnetic field ( Wang et al, 2021 ) and electric field ( Liu et al, 2021a ). The former reveals the function of cytoplasmic channels in myelin sheath as a coil inductor and the role of the magnetic field in the neural signal.…”