The Location and Morphology of Astrocyte, Tancyte, and Radial Glial Cells in the Neonatal Rat Brain
Loading...
Authors
Sayre, Ronald
Issue Date
1984
Type
Thesis
Language
en_US
Keywords
Alternative Title
Abstract
Studies have been done which examined the development
and differentiation of both neuronal and glial (astrocyte)
cells in only certain areas of the brain, including the
cerebral ventricular zone of the fetal monkey (Levitt, Cooper,
and Rakic, 1981), the superficial layers of early postnatal
mouse neocortex (Konig & Schachner, 1981), and the rat embryo
(Raju, Bignami, & Dahl, 1981).
This study is the first in which the location, morphology,
and degree of immunostaining of astrocyte, tanycyte, and radial
glial cells were examined in the entire postnatal brain in
2, 5, and 10 day old rats through the development of glial
fibrillary acidic (GFA) protein. GFA protein is a major
component of filaments in fibrous astroglial cells of the CNS,
and is also found in tanycyte and radial cells.
Normal white rats at 2, 5, and 10 days of age were sacrificed
and their brains were cut transversely with a vibrotome
into 60 urn thick serial sections. The unlabeled antibody
peroxidase-anti peroxidase (PAP) method was the immunocytochemical
technique used to stain the GFAP-containing glial
cells in the tissue.
Generally, white matter fiber tracts, including the corpus
callosum, optic tract, ventral hippocampal commissure, and
anterior commissure at 10 days of age contained a large number
of well differentiated astrocytes with many well branched
processes emanating from their cell bodies. Further, these
astrocyte cell bodies were present in rows which ran parallel
to the axons of the tracts. At 2 and 5 days of age, though,
white fiber tracts contained a smaller number of astrocytes.
These astrocytes were truncate in shape with very few processes.
Thus, a great deal of glial differentiation and maturation
occurs between 5 and 10 days of age.
Ependymal tanycytes were present in the dorso-medial
corners of the lateral ventricles (at the level of the lateral
septal nucleus) in 2, 5, and 10 day old rats. However,
there were fewer and smaller tanycytes in the 2 day old animals
in this area; in the older animals the tanycytes were thicker,
longer, and were running in one direction toward the midline.
Also, the processes of astrocytes located in the ventral
portion of the corpus callosum came into contact with the
ependymal tanycyte processes of the lateral ventricles. Thus,
there may be an astrocyte-tanycyte interaction.
Radial glia processes were observed in the area of the
rat cortex above the corpus callosum at 2 and 5 days of age.
At 10 days of age, though, no radial glia processes were seen
in this area; instead, small but well branched astrocytes
were present. Thus, it was thought that the radial glia
cells transformed postnatally into astrocytes. During embryonal
life, the radial glia may serve as guides for migrating
microneurons in the cortex.
Description
v, 66 p.
Citation
Publisher
License
U.S. copyright laws protect this material. Commercial use or distribution of this material is not permitted without prior written permission of the copyright holder. All rights reserved.