A low-angle X-ray diffraction study of the swelling behavior of peripheral nerve myelin

Abstract

The swelling behavior of peripheral nerve myelin has been studied by recording low-angle X-ray diffraction patterns of nerve after various chemical treatments. Peripheral myelin swells in distilled water, hypotonic Ringer's solution and sucrose solutions. The resulting low-angle pattern is called a swollen pattern (by comparison, the normal pattern is obtained from live nerve). The swelling of myelin is reversed by a reimmersion of the nerve in salt solutions and the resulting low-angle pattern is called a subnormal pattern. A relationship between these three kinds of patterns is given in terms of the width of the membrane pair. The forces between the adjacent membrane pairs in swollen myelin are likely to be long-range attractive Van der Waals' and long-range electrical repulsive forces. However, an equilibrium between the attrative and repulsive forces has not been observed.