Glial fibrillary acidic protein (GFAP)-like immunoreactivity in the rodent eye: Comparison between peripheral glia of the anterior uvea and central glia of the retina

Abstract

Immunohistochemistry with antiserum raised against glial fibrillary acidic protein (GFAP) revealed a dense plexus of GFAP-positive fibers in normal rodent iris. These fibers were not stained with 2 monoclonal GFAP antibodies which readily stain astrocytes, suggesting that they contain a polypeptide closely related, but not identical, to CNS GFAP. The GFAP-positive iris fibers did not disappear after short-term intraocular grafting or culturing of irides; instead a conspicuous system of fluorescent, star-shaped cells appeared. In the retina Müller glia were intensely fluorescent using GFAP antiserum whereas positive staining was observed with GFAP monoclonals only after injury to the retina. These antibodies, however, readily stained astrocytes in the inner layers of the normal retina. Taken together, these findings support the idea of GFA proteins as a group of closely related but not identical polypeptides.