ISSN:
1432-0878
Keywords:
Microglia
;
“M” cells
;
Gliogenesis
;
Neuropathology
;
Electron microscopy
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Summary Electron microscopy of subependymal cells and microglia in rat neonatal spinal cord reveals the latter to be a distinctive group of non-neuronal elements characterized by pronounced heterochromatin nuclei, many free ribosomes and rosettes, hour-glass shaped mitochondria, a moderately dense, granular cytoplasmic matrix, lipid vacuoles and a wide variety of lysosomes. Some examples are elongated and ameboid in appearance or may contain phagocytic vacuoles. Transitional forms between subependymal cells, or any other nonneuronal forms, and microglia were not observed. Ultrastructural features displayed by microglia are also strikingly characteristic of the “M” cells (Matthews and Kruger, 1973a, b) encountered in zones of thalamic degeneration two to three weeks following cortical ablation of adult rabbits. During the first and second postoperative weeks, “M” cells closely resemble the agranular leukocytes accumulating in the perivascular space of vessels coursing within the zones of degeneration. This fact, together with documentation of penetration of the vascular external lamina by elements of similar morphology, indicates a mesodermal origin for some “M” cells. The microglia of normal CNS and “M” cells of pathologic neural tissue are sufficiently similar, both in morphology and apparent function, to warrant consideration of a mesodermal origin for the microglia of neonatal CNS and a number of criteria to substantiate this concept are presented.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00221932
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