The determination of the fourier transform of the myelin layer from a study of swelling phenomena

Phase assignment to diffraction patterns based on the analytic properties of scattered fields applied to the structure of nerve myelin

“…3(b) was obtained. This figure suggests that the repeating unit of optic nerve contains four membranes as was originally suggested by Finean & Burge (1963)and also McIntosh & Robertson (1976) on the basis of electron microscopy.…”

“…2(d) which is heavily distorted and not confined to a finite interval on the 7-axis as required. However, the signs determined, by this method, for the six loops of the continuous transform include the -+ -signs for the first three loops as first determined by Finean & Burge (1963) and are identical with the set of six loops marginally favoured by Worthington & McIntosh (1973, 1974 on the basis of deconvolution and sampling-theorem approaches. A range of linear phase factors must be applied to the calculated phase in order to overcome the distortions and identify the phase for each intensity lobe.…”

“…For membranes, it is possible (Finean & Burge, 1963) to swell the structure, or rather the interval between units, resulting in additional diffraction patterns which hopefully sample the same continuous function corresponding to the transform of Q(r). It is inevitable that there will be systematic errors in the intensity profile following this procedure.…”

Evidence of alkane synthesis by the sciatic nerve of the rabbit

“…These results clearly demonstrate, for the first time, that alkanes may be synthesized by mammalians. That relatively high synthesizing activity may be related to the high alkane amounts we found in brain myelin [7] or in the peripheral nerve. On the basis of analysis done with brain myelin from normal and Quaking mice we postulated recently a possible relationship between very long-chain fatty acids and alkanes [9].…”

Paracrystalline nature of myelin

“…The lamellar structure of native frog sciatic nerve myelin has a one-dimensional periodicity, d, measured by Xray diffraction of 170 A and gives up to 16 low-order X-ray reflections. Innumerable attempts have been made to use the X-ray data to obtain the electron density profile of myelin (Finean, 1962;Finean & Burge, 1963: Burge & Draper, 1965Akers & Parsons, 1970;Harker, 1972;Worthington & McIntosh, 1974;Caspar & Kirschner, 1971). In all of these studies the myelin lamellar stacking was implicitly assumed to be crystalline.…”