Choline acetyltransferase (CAT) and muscarinic cholinergic receptor (MCR) activities are markedly reduced in aged as compared with young-adult rat brain. Nicergoline was found to correct these reduced activities in most regions of the brain, especially in the cerebral cortex and hippocampus. Chronic administration of nicergoline had no effect on CAT activity or MCR binding in young-adult rat brain. Nicergoline thus appears to have a specific therapeutic effect on cholinergic functions in aged rat brain, where it acts both pre-synaptically and post-synaptically.