Age related changes of various markers of astrocytes in senescence-accelerated mice hippocampus.

Astrocytes play a critical role in maintaining normal brain physiology during development and in adulthood, while to date the changes of astrocytes during aging and their effects on age-related functional decline have not been well understood. This study used immunohistochemistry, western blot, and reverse transcriptase polymerase chain reaction techniques to investigate the expression of glial fibrillary acidic protein (GFAP), glutamine synthetase (GS), and S100 beta proteins and mRNAs in the hippocampi of 3 months old and 16 months old senescence-accelerated-prone mice (SAMP8) and senescence-accelerated-resistant mice (SAMR1). The results showed significant age-related increases in both protein and mRNA levels of GFAP in the hippocampi of aged SAMP8 and SAMR1. As well, the GFAP of aged SAMP8 was significantly greater than that of aged SAMR1. However, no such increase was observed for either GS or S100 beta. These results suggested that GFAP, rather than GS or S100 beta, played a more important role in the age related deficits in learning and memory.