1. Department of Neurology, Oslo University Hospital, N-0027 Oslo, Norway
2. GliaLab and Letten Centre, Division of Physiology, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, N-0317 Oslo, Norway
3. Department of Molecular Neurobiology, Max Planck Institute for Medical Research, D-69120 Heidelberg, Germany
4. Max Planck Research Group at the Institute for Anatomy and Cell Biology, Heidelberg University, D-69120 Heidelberg, Germany
5. Division of Physiology, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, N-0317 Oslo, Norway
6. Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, N-0317 Oslo, Norway