1. Department of Neurosurgery; Oslo University Hospital, Rikshospitalet; Oslo 0027, Norway
2. Institute of Clinical Medicine, Faculty of Medicine; University of Oslo; Oslo Norway
3. GliaLab and Letten Centre, Division of Physiology, Department of Molecular Medicine; Institute of Basic Medical Sciences, University of Oslo; Oslo 0317 Norway
4. Department of Neurology; Oslo University Hospital, Rikshospitalet; Oslo 0027, Norway
5. Department of Medical Biochemistry and Cell Biology; Institute of Biomedicine, University of Gothenburg; Göteborg Sweden