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Elektronenmikroskopischer Beitrag zur Differenzierung des Ependyms am Rückenmark von Hühnerembryonen

Elektronenmikroskopischer Beitrag zur Differenzierung des Ependyms am Rückenmark von Hühnerembryonen An electronmicroscopic study of the ependymal differentiation and the development of the central canal has been carried out on the spinal cord of chicken embryos incubated for 2, 3, 41/2, 51/2, 8, 81/2, 9, 13 and 16 days old. The ependymal cells arise from the undifferentiated matrix cells. The first stage of differentiation is the formation of primitive and polar glioblasts (“spongioblasts”) in the region of the basal and roof plates. The fine structure of the polar glioblasts differs in the regions of the internal processes, the perikarya and the long processes extending towards the surface of the neural tube. The cytoplasmic differentiation within the internal region of these glioblasts is characterized by the development of diverse microvilli and of cilia on the surface, the accumulation of mitochondria and the development of a prominent Golgi apparatus in the cytoplasm. The synthesis of glial filaments occurs only in the peripheral processes. In the region of the perikaryon there are numerous free ribosomes and some profiles of a granular endoplasmic reticulum. The differentiation of the polar glioblasts into ependymal cells leads to a modified bipolar glial-epithelial structure. On the other hand, the transformation of the polar glioblasts into migrating glioblasts and finally into protoplasmatic and fibrous astrocytes—studied in the region of the glial septum dorsale—is characterized by a retraction of the internal processes with loss of epithelial differentiation. During all stages of development the ependymal cells retain their basic bipolarity, but time-related modifications of this nature can be observed. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Cell and Tissue Research Springer Journals

Elektronenmikroskopischer Beitrag zur Differenzierung des Ependyms am Rückenmark von Hühnerembryonen

Wechsler, Wolfgang
Cell and Tissue Research , Volume 74 (3) – Sep 1, 1966
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References (7)

Publisher
Springer Journals
Copyright
Copyright © 1966 by Springer-Verlag
Subject
Biomedicine; Neurosciences; Endocrinology; Neurology; Cell Biology
ISSN
0302-766X
eISSN
1432-0878
DOI
10.1007/BF00401265
Publisher site
See Article on Publisher Site

Abstract

An electronmicroscopic study of the ependymal differentiation and the development of the central canal has been carried out on the spinal cord of chicken embryos incubated for 2, 3, 41/2, 51/2, 8, 81/2, 9, 13 and 16 days old. The ependymal cells arise from the undifferentiated matrix cells. The first stage of differentiation is the formation of primitive and polar glioblasts (“spongioblasts”) in the region of the basal and roof plates. The fine structure of the polar glioblasts differs in the regions of the internal processes, the perikarya and the long processes extending towards the surface of the neural tube. The cytoplasmic differentiation within the internal region of these glioblasts is characterized by the development of diverse microvilli and of cilia on the surface, the accumulation of mitochondria and the development of a prominent Golgi apparatus in the cytoplasm. The synthesis of glial filaments occurs only in the peripheral processes. In the region of the perikaryon there are numerous free ribosomes and some profiles of a granular endoplasmic reticulum. The differentiation of the polar glioblasts into ependymal cells leads to a modified bipolar glial-epithelial structure. On the other hand, the transformation of the polar glioblasts into migrating glioblasts and finally into protoplasmatic and fibrous astrocytes—studied in the region of the glial septum dorsale—is characterized by a retraction of the internal processes with loss of epithelial differentiation. During all stages of development the ependymal cells retain their basic bipolarity, but time-related modifications of this nature can be observed.

Journal

Cell and Tissue Research – Springer Journals

Published: Sep 1, 1966

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