Age-related changes in glial fibrillary acidic protein mRNA in the mouse brain.

Several RNA sequences were tested for age-related changes in prevalence levels in the mouse cerebral cortex, hippocampus, and cerebellum. In all three regions, there were increased levels of RNA for glial fibrillary acidic protein, an astrocyte-specific protein, by RNA gel-blot analysis and by a solution hybridization assay. There was no change in glutamine synthetase mRNA level, another glial protein. The only other mRNA sequence which changed was Thy-1 antigen, a neuronal protein, which decreased slightly in the hippocampus. We conclude that with age there is an age-related increase in glial fibrillary acidic protein RNA prevalence potentially reflecting an increase in the size, number, and/or fibrous character of astrocytes.