The present invention provides methods for increasing secretion of dopamine and other neurotransmitters and treating or reducing the incidence of diseases involving decreased secretion of dopamine and other neurotransmitters, e.g. Parkinson's disease, comprising administering to the subject a uridine or a source thereof, and compositions for treating or reducing an incidence of Parkinson's disease, comprising a uridine, a uridine monophosphate, or a source thereof.