Eur. Phys. J. E (2006) 19: 399-412
https://doi.org/10.1140/epje/i2005-10054-2

Regular Article

Theory of myelin coiling

James Franck Institute and Department of Physics, University of Chicago, 5640 South Ellis Avenue, 60637, Chicago, IL, USA

^* e-mail: jhuang2@uchicago.edu

Received: 3 November 2005
Accepted: 18 January 2006
Published online: 8 February 2006

Abstract

A new model is proposed to explain coiling of myelins composed of fluid bilayers. This model allows the constituent bilayer cylinders of a myelin to be non-coaxial and the bilayer lateral tension to vary from bilayer to bilayer. The calculations show that a myelin would bend or coil to lower its free energy when the bilayer lateral tension is sufficiently large. From a mechanical point of view, the proposed coiling mechanism is analogous to the classical Euler buckling of a thin elastic rod under axial compression. The analysis of a simple two-bilayer case suggests that a bilayer lateral tension of about 1 dyne/cm can easily induce coiling of myelins of typical lipid bilayers. This model signifies the importance of bilayer lateral tension in determining the morphology of myelinic structures.