The number of neurological conditions associated with the mutant prion protein continues to grow. The list includes BSE and scrapie, which affect cattle and sheep respectively, and Creutzfeldt-Jacob Disease, which affects humans. This is an area of intense interest to neuroscientists, veterinary scientists, and clinicians. It has also attracted significant media attention because of the potential risks to humans. This book brings together leading researchers in the field to provide an up-to-date and authoritative summary of the field.