title: Changes of statistical structural fluctuations unveils an early compacted degraded stage of PNS myelin.
abstract: Degradation of the myelin sheath is a common pathology underlying demyelinating neurological diseases from Multiple Sclerosis to Leukodistrophies. Although large malformations of myelin ultrastructure in the advanced stages of Wallerian degradation is known, its subtle structural variations at early stages of demyelination remains poorly characterized. This is partly due to the lack of suitable and non-invasive experimental probes possessing sufficient resolution to detect the degradation. Here we report the feasibility of the application of an innovative non-invasive local structure experimental approach for imaging the changes of statistical structural fluctuations in the first stage of myelin degeneration. Scanning micro X-ray diffraction, using advances in synchrotron x-ray beam focusing, fast data collection, paired with spatial statistical analysis, has been used to unveil temporal changes in the myelin structure of dissected nerves following extraction of the Xenopus laevis sciatic nerve. The early myelin degeneration is a specific ordered compacted phase preceding the swollen myelin phase of Wallerian degradation. Our demonstration of the feasibility of the statistical analysis of SµXRD measurements using biological tissue paves the way for further structural investigations of degradation and death of neurons and other cells and tissues in diverse pathological states where nanoscale structural changes may be uncovered.
authors: 1] RICMASS Rome International Center for Materials Science Superstripes, via dei Sabelli 119A, 00185 Roma, Italy [2] MESA+ Institute for Nanotechnology, University of Twente, P. O. Box 217, 7500AE Enschede, The Netherlands [3].
authors: Nicola
authors: N
authors: Poccia
authors: 1] Institute of Crystallography, CNR, via Salaria Km 29.300, 00015 Monterotondo Roma, Italy [2].
authors: Gaetano
authors: G
authors: Campi
authors: 1] RICMASS Rome International Center for Materials Science Superstripes, via dei Sabelli 119A, 00185 Roma, Italy [2] Deutsches Elektronen-Synchrotron DESY, Notkestraβe 85, D-22607 Hamburg, Germany.
authors: Alessandro
authors: A
authors: Ricci
authors: RICMASS Rome International Center for Materials Science Superstripes, via dei Sabelli 119A, 00185 Roma, Italy.
authors: Alessandra S
authors: AS
authors: Caporale
authors: European Synchrotron Radiation Facility, B. P. 220, F-38043 Grenoble Cedex, France.
authors: Emanuela
authors: E
authors: Di Cola
authors: Department of Cell and Developmental Biology, UCL, Gower Street, WC1E 6BT London, UK.
authors: Thomas A
authors: TA
authors: Hawkins
authors: 1] RICMASS Rome International Center for Materials Science Superstripes, via dei Sabelli 119A, 00185 Roma, Italy [2] Institute of Crystallography, CNR, via Salaria Km 29.300, 00015 Monterotondo Roma, Italy.
authors: Antonio
authors: A
authors: Bianconi
mesh_terms: D000818:Animals; D001369:Axons / Q000473:pathology*; D002478:Cells, Cultured; D003711:Demyelinating Diseases / Q000473:pathology; D005260:Female; D006801:Humans; D009103:Multiple Sclerosis / Q000473:pathology; D009186:Myelin Sheath / Q000473:pathology*; D017933:Peripheral Nervous System / Q000473:pathology*; D012584:Sciatic Nerve / Q000473:pathology; D017356:Synchrotrons; D014855:Wallerian Degeneration / Q000473:pathology*; D014961:X-Ray Diffraction / Q000379:methods; D014982:Xenopus laevis