Aging in rodent brain: alteration in astrocyte population

A method for the preparation of bulk isolated glial cells was modified to provide astrocytes suitable for biochemical analysis. Using this method, the astrocyte-enriched fraction from senescent mouse or rat brain stem could not be recovered from the sucrose interface at which 6 month brain stem astroglia accumulated. An alteration in the buoyant density of the senescent glial cells was demonstrated by using continuous diatrizoate gradients. The involvement of the astrocyte cell population in this age-related shift in buoyant density was confirmed using antiserum specific for glial fibrillary acidic protein.