ISSN:
1432-0568
Keywords:
Astrocytes
;
Endothelial junctions
;
Cerebral vessels
;
Optic tectum
;
Chick embryo
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract The role played by perivascular astrocytes in neural vessel maturation was investigated in microvessels of the chick embryo optic tectum. Three-dimensional reconstructions and quantitative analyses were made, and permeability was studied. On embryonic days 14–16, 12.5% of the microvessel wall is surrounded by astrocyte endfeet which, in most cases (82%), are located under endothelium junctions; the latter, at this stage, partly prevent the extravascular escape of the marker horseradish peroxidase. On days 18–21, the astrocyte processes form a nearly complete perivascular sheath enveloping 96% of the microvessel perimeter; the junctions of the endothelial cells are much wider and impermeable owing to extensive fusion of the endothelial plasma membranes. This investigation suggests a close relationship between the perivascular arrangement of glia and differentiation of the endothelium tight junctions and indicates that the morphofunctional maturation of the latter takes place progressively during the prenatal organogenesis of the chick central nervous system.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00191448
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