1. Wellcome Trust – Medical Research Council Cambridge Stem Cell Institute, University of Cambridge, Cambridge CB2 1QR, United Kingdom;
2. Department of Veterinary Medicine, University of Cambridge, Cambridge CB3 0ES, United Kingdom
3. Departments of Cell Biology and Neurobiology, Duke University School of Medicine, Durham, North Carolina 27710, USA;
4. Preston Robert Tisch Brain Tumor Center, Duke University Medical Center, Durham, North Carolina 27710, USA
5. Institute for Brain Sciences, Duke University, Durham, North Carolina 27708, USA