title: New X-ray spacings from central myelinated tissue.
abstract: New X-ray reflections have been detected from myelinated tissue of the mammalian C.N.S. Diffraction patterns from unfixed optic nerves of mouse, rat, guinea-pig and rabbit, and unfixed corpus callosum of calf were recorded during X-ray exposures of 1-6 days. The equatorial pattern was typical of lamellar myelin of the C.N.S.; however, the meridional pattern showed new features: a strong, sharp intensity maximum at 30.4 +/- 0.4 A (N = 11) spacing, and a weak, diffuse ring centered at 11.0 +/- 0.5 A (N = 5) spacing. The 30.4 A reflection was neither strictly arced like the equatorial reflections from lamellar myelin nor fully horizontal. Since the 30.4 A meridional reflection was not observed in patterns from myelinated nerve of the P.N.S., we suggest that this diffraction comes from the radial component, or interlamellar tight junctions, which is unique to mammalian C.N.S. myelinated tissue. The diffuse ring at 11.0 A probably comes from myelin protein.
mesh_terms: D000818:Animals; D002417:Cattle; D003337:Corpus Callosum / Q000648:ultrastructure*; D006168:Guinea Pigs; D007365:Intercellular Junctions / Q000648:ultrastructure; D051379:Mice; D008818:Mice, Neurologic Mutants; D009185:Myelin Proteins; D009186:Myelin Sheath / Q000648:ultrastructure*; D009900:Optic Nerve / Q000648:ultrastructure*; D009928:Organ Specificity; D010525:Peripheral Nerves / Q000648:ultrastructure; D011817:Rabbits; D051381:Rats; D013045:Species Specificity; D014961:X-Ray Diffraction
chemical_list: D009185:Myelin Proteins