1. Department of Physics, Chemistry and Biology, Linköping University, Linköping 581 83, Sweden
2. Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy, University of Gothenburg, Mölndal Hospital, Mölndal 431 80, Sweden
3. Department of Neurodegenerative Diseases, University College London Institute of Neurology, Queen Square, London WC1N 3BG, United Kingdom
4. Department of Pathology and Laboratory Medicine, Indiana University School of Medicine, Indianapolis, Indiana 46202, United States