Jack van Horssen is trained as a neurobiologist with a keen interest in neuropathology. Already during his masters he could easily spend hours behind the microscope to grasp the complexity of the central nervous system. During his PhD his interest in understanding the cellular organization of the brain and the pathological changes underlying neurological disorders was further strengthened. Besides his active role in teaching bachelor students medicine he, and his colleagues, have been working on understanding the pathological alterations that drive multiple sclerosis disease progression. During his talk, he will give insight into basic aspects of the brain and provide a comprehensive overview on the mystery of multiple sclerosis pathology, a disease that affects over 2.3 million young adults worldwide.