The Astroglial Response to Stabbing. Immunofluorescence Studies With Antibodies to Astrocyte‐specific Protein (Gfa) in Mammalian and Submammalian Vertebrates

The astroglial response t o stabbing. Immunofluorescence studies with antibodies to astrocyte‐specific protein (GFA) in mammalian and sub‐mammalian vertebrates The astroglial response to stabbing was studied by immunofluorescence with GFA protein antisera in adult and newborn rats, chickens and goldfish. In the adult normal rat most astrocytes of the isocortex and corpus striatum are protoplasmic and do not stain by immunofluorescence. Two days after injury many astrocytes became brightly fluorescent in the stabbed hemisphere and were still fluorescent 2 months later. In the newborn rat the astroglial response was more limited. Reactive glial cells in the medial frontal cortex and pyramidal layer of the hippocampus had a radial appearance with thin immunofluorescent processes crossing at right angles to the surface of the cortex. In rats stabbed at birth and killed 1 month later many immunofluorescent astrocytes were present in the frontal cortex of both cerebral hemispheres. Radial glia were no longer observed. In the normal adult rat radial glial processes were seen by immunofluorescence extending at right angles from the lateral wall of the third ventricle into the hypothalamus. In the chicken cerebellum the astroglial response to stabbing was limited, with few immunofluorescent fibers in the vicinity of the wound. No changes were observed in the goldfish optic tectum by immunofluorescence.