1. Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, CA 94143, USA.
2. Department of Neurology, University of California, San Francisco, CA 94158, USA.
3. Department of Pediatrics, University of California, San Francisco, CA 94143, USA.
4. Department of Neurology, Medical Faculty Mannheim, University of Heidelberg, 68167 Mannheim, Germany.
5. Genomics Institute, University of California, Santa Cruz, CA, USA.
6. Hertie Institute for Clinical Brain Research, University of Tübingen, 72076 Tübingen, Germany.
7. Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA.
8. Department of Paediatrics and Wellcome Trust–MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge CB2 0QQ, UK.
9. Department of Neurosurgery, University of California, San Francisco, CA 94143, USA.