Morphometric analysis of myelinated axons during maturation in the fasciculus gracilis and fasciculus cuneatus of rats. A transmission electron microscopy study
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Data
2001
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Resumo
The process of myelination is an important event in the maturation of the nervous system. In this study, the fasciculus gracilis
and fasciculus cuneatus in the first and sixth cervical segments of the spinal cord of a mutant strain of Wistar rats, were studied
by electron microscopy in order to determine the perimeter of the axons, the thickness of the myelin sheath, and the diameter
and perimeter of the nerve fibers. At birth, the fasciculus gracilis and fasciculus cuneatus had unmyelinated fibers, but by the
fifth day after birth myelination was in progress. The mean perimeter of nerve fibers was significantly greater (p< 0.05) in the
fasciculus cuneatus compared to the fasciculus gracilis at 15, 20 and 120 days of age. The diameter of the fibers, perimeter of
the axons and thickness of the myelin sheath were more developed in the fasciculus cuneatus than in the fasciculus gracilis at
all ages studied. The axons were relatively thinner 15-20 days after birth than at 20-120 days after birth. The myelination of the
fasciculi gracilis and cuneatus in the spinal cord of this mutant strain, agreed with previous reports indicating that the mutation,
which causes the rats to have bare skin, had no significant effect on myelination in the anatomical areas studied.
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Axons, Fasciculi cuneatus and gracilis, Morphometry, Myelination, Transmission electron microscopy
Citação
MATA, José Roberto da; MORAIS, José Oscar Rodrigues de; SABÓIA-MORAIS, Simone Maria Teixeira. Morphometric analysis of myelinated axons during maturation in the fasciculus gracilis and fasciculus cuneatus of rats. A transmission electron microscopy study. Brazilian Journal of Morphological Sciences, São Paulo, v. 18, n. 1, p. 1-6, 2001.