In the past five years significant progress has been made in our basic and clinical under standing of Parkinson's disease. The discovery that MPTP, a relatively simple molecule, is able to induce parkinsonism in otherwise healthy adult humans, and the recent interest in the possibility of "transplantation" procedures as a therapeutic modality in the treatment of Parkin son's disease have generated enormous interest in research related to Parkinson's disease. In this setting, the National Parkinson Foundation decided to organize a research meeting to bring together scientists actively engaged...