Early appearance of type II astrocytes in developing human fetal brain.
To compare rat and human glial development, we examined the cellular composition of human fetal brain in short-term cultures and fresh cell suspensions from fetal ages ranging from 7 to 16 weeks, utilizing the cell type-specific markers which define glial subsets in rats. Here we report that unlike the early rat central nervous system (CNS), 7-10 week human fetal brain contains mostly astrocytes that can be characterized as type II rather than type I. Type I astrocytes become more prevalent in 16-week gestational age human brain. Although cells morphologically and immunocytochemically similar to the rat 02-A cell are found in human fetal brain and spinal cord, these cells were not induced to express galactocerebroside in serum-free media and did not have vimentin-containing intermediate filaments as do rat 02-A cells. These results suggest that functional differences may exist between rat type I and type II astrocytes and phenotypically similar cells found in humans.
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Infectious Diseases Branch, DIR, National Institute of Neurological and Communicative Disorders and Stroke, Bethesda, MD 20892.
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D001253:Astrocytes / Q000378:metabolism / Q000502:physiology*; D001921:Brain / Q000166:cytology / Q000196:embryology*; D002478:Cells, Cultured; D005865:Gestational Age; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry
D005904:Glial Fibrillary Acidic Protein