Aging reduces the mRNA of alpha 1 GABAA receptor subunit in rat cerebral cortex

The effect of aging on the binding of ligands to the GABA, benzodiazepine and picrotoxin binding sites as well as alpha subunit mRNA level of GABAA receptor was investigated in cerebral cortex of male Fischer F-344 rats. In aged (730- to 770-day-old) rats, the binding of [35S]t-butylbicyclophosphorothionate (TBPS) was significantly reduced. Also, alpha 1 mRNA level was markedly decreased (86% suppression). In contrast, alpha 1 mRNA remained unchanged in cerebellum. These findings indicate a selective age-related structural change in GABAA receptor in rat cerebral cortex.