The present invention is directed to methods of ameliorating hippocampal dysfunction and improving or inhibiting decline in intelligence or cognitive or hippocampal-dependent memory of a subject and of increasing synthesis and release of neurotransmitters, neurite outgrowth, and levels of neurofilament proteins in the brain and CNS of a subject, comprising administering to the subject a uridine, an acyl derivative thereof, a uridine phosphate, uracil, or a salt thereof.