1. Institute for Neuroscience and Medicine II, Molecular Organization of the Brain Research Center Juelich Julich Germany
2. Department of Nuclear Medicine University of Cologne, Faculty of Medicine and University Hospital Cologne Cologne Germany
3. Faculty of Mathematics and Natural Sciences University of Cologne Cologne Germany
4. German Center for Neurodegenerative Diseases (DZNE) Bonn/Cologne Germany
5. Department of Neurology, Faculty of Medicine and University Hospital Cologne University of Cologne Cologne Germany