title: Quantitative studies on proliferative changes of reactive astrocytes in mouse cerebral cortex.
abstract: Cell number and proliferation of reactive astrocytes were studied quantitatively in the stabbed cerebral cortex of adult mice, using immunohistochemistry for glial fibrillary acidic protein (GFAP) and [3H]thymidine autoradiography. GFAP-positive astrocytes increased in cell number gradually from 24 to 96 h after stabbing, and their immunoreactivity became intense. The maximum number of GFAP-positive cells was about 4.5 times normal in the layers II-VI of the cortex, whereas it was only 1.5 times normal in the layer I (molecular layer). In contrast to the gradual increase in cell number, no GFAP-positive astrocytes were labeled with [3H]thymidine prior to 48 h after stabbing, in either the layer I or the layers II-VI. Then 3-5% of them were labeled at 72 and 96 h, but very few again after 6 days. By injecting [3H]thymidine successively for 6 days after stabbing, only 17% of GFAP-positive astrocytes of the layer I or the layers II-VI were labeled. These results reveal that, in the cortical layers II-VI, many GFAP-negative source cells initially express much more GFAP-antigen without proliferation and change into GFAP-positive reactive astrocytes. Proliferation of reactive astrocytes is not the major factor for the marked increase in number of them. The cortical layer I would have few GFAP-negative source cells for reactive astrocytes. These source cells may be protoplasmic astrocytes.
authors.affiliation: Department of Pathology, Fukui Medical School, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Miyake
authors.forename: T
authors.initials: T
authors.lastname: Hattori
authors.forename: M
authors.initials: M
authors.lastname: Fukuda
authors.forename: T
authors.initials: T
authors.lastname: Kitamura
authors.forename: S
authors.initials: S
authors.lastname: Fujita
mesh_terms: D000818:Animals; D001253:Astrocytes / Q000166:cytology*; D002455:Cell Division; D002540:Cerebral Cortex / Q000166:cytology*; D005904:Glial Fibrillary Acidic Protein; D051379:Mice; D008813:Mice, Inbred ICR; D051381:Rats
chemical_list: D005904:Glial Fibrillary Acidic Protein