Myelination of Callosal Axons Is Hampered by Early and Late Forelimb Amputation in Rats
| Autor: | Roberto Lent, Patricia P. Garcez, Fernanda Tovar-Moll, Carlomagno Pacheco Bahia, Alexandre Sanabio, Rodrigo Vianna-Barbosa, Rodrigo Madeiro da Costa, Gabriella P A de Freitas, Kildare Miranda |
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| Rok vydání: | 2020 |
| Předmět: |
0301 basic medicine
somatosensory cortex medicine.medical_treatment Biology Somatosensory system Corpus callosum White matter corpus callosum 03 medical and health sciences 0302 clinical medicine amputation Fractional anisotropy medicine General Environmental Science Cerebral peduncle myelination Anatomy 030104 developmental biology medicine.anatomical_structure Amputation Corticospinal tract morphological plasticity General Earth and Planetary Sciences Original Article Forelimb 030217 neurology & neurosurgery |
| Zdroj: | Cerebral Cortex Communications |
| ISSN: | 2632-7376 |
| Popis: | 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. |
| Databáze: | OpenAIRE |
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