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Cortical Type 2 Astrocytes are not Dye Coupled nor do they Express the Major Gap Junction Genes found in the Central Nervous System
Glia (1994)
  • Daniel Belliveau, The University of Western Ontario
  • C. C.G. Naus
Abstract
The O‐2A progenitor cell first described from the rat optic nerve is a bipotential precursor of oligodendrocytes and type 2 astrocytes. Each cell expresses specific markers that distinguish them as unique cell types. O‐2A progenitors cultured in high serum preferentially differntiate into type 2 astrocytes and when exposed to defined medium or low serum develop along the oligodendrocyte lineage. We analyzed the gap junction gene expression of type 2 astrocytes to determine if they are coupled to form a syncytium, like their type 1 astrocyte counterparts. Dye coupling experiments demonstrated that cortical type 2 astrocytes are not coupled, while type 1 astrocytes in the same culture dish are highly coupled. Immunocytochemistry revealed the presence of Cx43 in type 1 astrocytes but we could not detect Cx26, 32, or 43 protein in type 2 astrocytes. In situ hybridization did not detect mRNA for any of the three connexin genes in type 2 astrocytes. These data demonstrate that type 2 astrocytes do not express the major gap junction genes found in the central nervous system. The precise function of type 2 astrocytes is not known but the lack of gap junction genes expression suggests that their functions are different from the spatial buffering capacity of type 1 astrocytes.
Keywords
  • 0-2A progenitor,
  • perinodal astrocytes,
  • cell culture,
  • connexins
Publication Date
1994
Citation Information
Daniel Belliveau and C. C.G. Naus. "Cortical Type 2 Astrocytes are not Dye Coupled nor do they Express the Major Gap Junction Genes found in the Central Nervous System" Glia Vol. 12 Iss. 1 (1994)
Available at: http://works.bepress.com/daniel_belliveau/17/