Axon morphology is modulated by the local environment and impacts the noninvasive investigation of its structure-function relationship.

Autor:	Andersson M; Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, 2650 Hvidovre, Denmark; mariama@drcmr.dk timd@drcmr.dk.; Department of Applied Mathematics and Computer Science, Technical University of Denmark, 2800 Kongens Lyngby, Denmark., Kjer HM; Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, 2650 Hvidovre, Denmark.; Department of Applied Mathematics and Computer Science, Technical University of Denmark, 2800 Kongens Lyngby, Denmark., Rafael-Patino J; Signal Processing Laboratory (LTS5), École Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland., Pacureanu A; The European Synchrotron, 38000 Grenoble, France., Pakkenberg B; Research Laboratory for Stereology and Neuroscience, Copenhagen University Hospital, Bispebjerg, 2400 Copenhagen, Denmark., Thiran JP; Signal Processing Laboratory (LTS5), École Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland.; Radiology Department, Centre Hospitalier Universitaire Vaudois and University of Lausanne, 1011 Lausanne, Switzerland.; Center for Biomedical Imaging, 1015 Lausanne, Switzerland., Ptito M; School of Optometry, University of Montreal, Montreal, QC H3T 1P1, Canada.; Department of Neuroscience, Faculty of Health Science, University of Copenhagen, 2200 Copenhagen, Denmark., Bech M; Division of Medical Radiation Physics, Department of Clinical Sciences, Lund University, 221 85 Lund, Sweden., Bjorholm Dahl A; Department of Applied Mathematics and Computer Science, Technical University of Denmark, 2800 Kongens Lyngby, Denmark., Andersen Dahl V; Department of Applied Mathematics and Computer Science, Technical University of Denmark, 2800 Kongens Lyngby, Denmark., Dyrby TB; Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, 2650 Hvidovre, Denmark; mariama@drcmr.dk timd@drcmr.dk.; Department of Applied Mathematics and Computer Science, Technical University of Denmark, 2800 Kongens Lyngby, Denmark.
Jazyk:	angličtina
Zdroj:	Proceedings of the National Academy of Sciences of the United States of America [Proc Natl Acad Sci U S A] 2020 Dec 29; Vol. 117 (52), pp. 33649-33659. Date of Electronic Publication: 2020 Dec 21.
DOI:	10.1073/pnas.2012533117
Abstrakt:	Axonal conduction velocity, which ensures efficient function of the brain network, is related to axon diameter. Noninvasive, in vivo axon diameter estimates can be made with diffusion magnetic resonance imaging, but the technique requires three-dimensional (3D) validation. Here, high-resolution, 3D synchrotron X-ray nano-holotomography images of white matter samples from the corpus callosum of a monkey brain reveal that blood vessels, cells, and vacuoles affect axonal diameter and trajectory. Within single axons, we find that the variation in diameter and conduction velocity correlates with the mean diameter, contesting the value of precise diameter determination in larger axons. These complex 3D axon morphologies drive previously reported 2D trends in axon diameter and g -ratio. Furthermore, we find that these morphologies bias the estimates of axon diameter with diffusion magnetic resonance imaging and, ultimately, impact the investigation and formulation of the axon structure-function relationship. Competing Interests: The authors declare no competing interest. (Copyright © 2020 the Author(s). Published by PNAS.)
Databáze:	MEDLINE
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