This book presents much of the exciting new information on mechanisms of neurodegenerative disorders that was presented at the XVth International Spring Symposium on Health Sciences at George Washington University in Washington, D.C. The organization of the symposium as weIl as the chapters within this book were based upon fundamental molecular and cellular mechanisms of neurodegeneration rather than upon different clinically defined disorders, in order to emphasize the commonality of cause rather than effect. The first part of the book is devoted to the relationships between selective vulnerability of different neuronal cell types to injury and their functional characteristics related to the transport, binding, and responses