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Fine structure of dividing astroglia and oligodendroglia during myelin formation in the developing mouse spinal cord
Author(s) -
Meinecke Douglas L.,
de F. Webster Henry
Publication year - 1984
Publication title -
journal of comparative neurology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.855
H-Index - 209
eISSN - 1096-9861
pISSN - 0021-9967
DOI - 10.1002/cne.902220105
Subject(s) - biology , myelin , spinal cord , mitosis , endoplasmic reticulum , anatomy , neuropil , white matter , electron microscope , organelle , ultrastructure , cytoplasm , microtubule , golgi apparatus , microbiology and biotechnology , central nervous system , neuroscience , medicine , physics , radiology , magnetic resonance imaging , optics
To study the morphology and cellular relationships of dividing glial cells during myelin formation, we perfused newborn and 5‐day mouse pups and embedded slices of cervical, thoracic, and lumbar cord for light and electron microscopic study. In semithin epon sections stained with toluidine blue, all levels of spinal cord at both ages contained mitotic glia in gray columns and funiculi. In electron micrographs of funiculi, dividing astroglia contained bundles of glial filaments, many glycogen granules, and had large processes extending into the surrounding neuropil. Cytoplasmic organelles of many immature interphase oligodendroglia and mitotic oligodendroblasts were similar and included microtubules, clusters of free ribosomes, and scattered profiles of granular endoplasmic reticulum. Unlike astroglia, dividing oligodendroblasts lacked large processes and in metaphase they were ellipsoids and had smooth plasma membranes. When these cells were studied in alternating serial thin and semithin sections over 10–15‐μm distances, we did not identify connections between myelin sheaths and mitotic oligodendroblasts. Our findings indicate that oligodendroglia in developing white matter multiply before developing large processes. Our data also suggest that oligodendroglia do not divide while forming myelin.