AGING IS ASSOCIATED WITH DIVERGENT EFFECTS ON NF-L AND GFAP TRANSCRIPTION IN RAT-BRAIN

We studied the effects of advancing age on the expression of several p roteins important in the structure and function of the nervous system. Brains of young (3 month), middle-aged (13 month), and old (29 month) male Fischer 344 rats were examined. Run-on transcription and Norther n blot hybridizations were used to determine gene-specific transcripti on rates and mRNA levels, respectively. With advancing age, there was a decrement in the transcription rate and mRNA levels for neurofilamen t-light subunit (Nf-L), but an increment in the transcription rate and mRNA levels for glial fibrillary acidic protein (GFAP). Proteolipid p rotein (PLP) mRNA levels were attenuated between 3 and 13 months of ag e, whereas amyloid precursor protein (APP) mRNA levels were attenuated in the middle-aged but not the old animals. Transcription rates for o c-actin and Sos, and mRNA levels for alpha-actin, were unaffected. The se observations indicate divergent transcriptional regulation of sever al genes, notably Nf-L and GFAP, in the aging mammalian forebrain. Cop yright (C) 1996 Elsevier Science Inc.