This lecture explores the application of Cryo-Electron Microscopy (Cryo-EM) in studying Parkinson's Disease, focusing on the nano-world of protein structures. It covers the resolution revolution in Cryo-EM, single particle Cryo-EM techniques, and the structure of human ABC transporters. The lecture delves into the challenges and advancements in imaging techniques, sample preparation, and the understanding of protein fibril growth. It also discusses the role of a-synuclein in neuronal death, Lewy body formation, and the spread of pathology in Parkinson's Disease.