AGE-RELATED-CHANGES OF CALBINDIN-D28K, CALRETININ, AND PARVALBUMIN MESSENGER-RNAS IN THE HAMSTER BRAIN

Changes of three different cytosolic Ca2+ binding proteins, calbindin- D28k, calretinin, and parvalbumin mRNA expression in the brain of the hamster during aging were investigated by in situ hybridization using brains from hamsters aged 3, 9, 13, 19, to 24 months old. In cerebellu m area, calbindin-D28k, transcripts showed about 50% to 68% decrease i n content in aged-hamster (19 and 24 months old) compared with young ( 4 months) and adult (9 months), whereas calretinin and parvalbumin mRN A expression remain unchanged throughout the ages examined. Calbindin- D28k gene expression was decreased during aging also in the hippocampu s (approximately 60% reduction) and stratum (approximately 25%). In th e same areas, striatum and hippocampus, calretinin and parvalbumin mRN A expression in the equivalent sections were not significantly changed with age. These data raise the possibility that CNS calbindin-D28k ex pression may be selectively down-regulated during aging. The statistic ally significant decrease of calbindin-D28k mRNA in the normal aging p rocess also suggests and provides further support for the hypothesis t hat this calcium binding protein may have an important role in neurona l degeneration. (C) 1998 Elsevier Science Inc.