Myelination of Callosal Axons Is Hampered by Early and Late Forelimb Amputation in Rats.

Autor: Vianna-Barbosa R; Post-Graduate Program in Morphological Sciences, Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro CEP 21941-902, Brazil.; National Center of Structural Biology and Bioimaging, Federal University of Rio de Janeiro, Rio de Janeiro CEP 21941-902, Brazil., Bahia CP; Institute of Health Sciences, Federal University of Pará, Pará CEP 66035-160, Brazil., Sanabio A; Post-Graduate Program in Morphological Sciences, Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro CEP 21941-902, Brazil., de Freitas GPA; Post-Graduate Program in Morphological Sciences, Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro CEP 21941-902, Brazil., Madeiro da Costa RF; D'Or Institute of Research and Education (IDOR), Rio de Janeiro, CEP 22281-100, Brazil., Garcez PP; Post-Graduate Program in Morphological Sciences, Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro CEP 21941-902, Brazil., Miranda K; National Center of Structural Biology and Bioimaging, Federal University of Rio de Janeiro, Rio de Janeiro CEP 21941-902, Brazil.; Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro CEP 21941-902, Brazil., Lent R; Post-Graduate Program in Morphological Sciences, Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro CEP 21941-902, Brazil.; D'Or Institute of Research and Education (IDOR), Rio de Janeiro, CEP 22281-100, Brazil., Tovar-Moll F; Post-Graduate Program in Morphological Sciences, Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro CEP 21941-902, Brazil.; National Center of Structural Biology and Bioimaging, Federal University of Rio de Janeiro, Rio de Janeiro CEP 21941-902, Brazil.; D'Or Institute of Research and Education (IDOR), Rio de Janeiro, CEP 22281-100, Brazil.
Jazyk: angličtina
Zdroj: Cerebral cortex communications [Cereb Cortex Commun] 2020 Nov 27; Vol. 2 (1), pp. tgaa090. Date of Electronic Publication: 2020 Nov 27 (Print Publication: 2021).
DOI: 10.1093/texcom/tgaa090
Abstrakt: Deafferentation is an important determinant of plastic changes in the CNS, which consists of a loss of inputs from the body periphery or from the CNS itself. Although cortical reorganization has been well documented, white matter plasticity was less explored. Our goal was to investigate microstructural interhemispheric connectivity changes in early and late amputated rats. For that purpose, we employed diffusion-weighted magnetic resonance imaging, as well as Western blotting, immunohistochemistry, and electron microscopy of sections of the white matter tracts to analyze the microstructural changes in the corticospinal tract and in the corpus callosum (CC) sector that contains somatosensory fibers integrating cortical areas representing the forelimbs and compare differences in rats undergoing forelimb amputation as neonates, with those amputated as adults. Results showed that early amputation induced decreased fractional anisotropy values and reduction of total myelin amount in the cerebral peduncle contralateral to the amputation. Both early and late forelimb amputations induced decreased myelination of callosal fibers. While early amputation affected myelination of thinner axons, late amputation disrupted axons of all calibers. Since the CC provides a modulation of inhibition and excitation between the hemispheres, we suggest that the demyelination observed among callosal fibers may misbalance this modulation.
(© The Author(s) 2020. Published by Oxford University Press.)
Databáze: MEDLINE
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