ISSN:
0003-276X
Keywords:
Life and Medical Sciences
;
Cell & Developmental Biology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Medicine
Notes:
In order to identify the onset of myelination as well as to clarify the development of glial cells in human cervical spinal cord 21 embryos and fetuses ranging from 5 weeks of ovulation age (16 mm in crown-rump length) to 13 weeks (110 mm) were examined with the light and electron microscope. The first appearance of definite myelinated fibers occurred in the lateral portion of the ventral marginal layer of a 66-mm (10-week) fetus. These nascent myelinated axons were always of larger diameter than unmyelinated axons. Although they occurred infrequently, there were, nevertheless, degenerative changes observed in some of these first myelinated axons in the 66-mm fetus. By this time glial cells in the marginal layer rapidly increased in number and substantial differentiation had occurred. Young oligodendrocytes are considered as the only myelin-forming cells in the human spinal cord.
Additional Material:
12 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/ar.1092020407
