[1] Univ Calif San Francisco, Dept Pediat, Eli & Edyth Broad Inst Stem Cell Res & Regenerat, San Francisco, CA 94143 USA
[2] Univ Calif San Francisco, Dept Neurosurg, Eli & Edyth Broad Inst Stem Cell Res & Regenerat, San Francisco, CA 94143 USA
[3] Univ Calif San Francisco, Howard Hughes Med Inst, San Francisco, CA 94143 USA
[4] Univ Calif San Francisco, Dept Neurol, San Francisco, CA 94143 USA
[5] Univ Calif San Francisco, Div Neonatol, San Francisco, CA 94143 USA
[6] Univ Cambridge, MRC Ctr Stem Cell Biol & Regenerat Med, Cambridge CB3 0ES, England
[7] Univ Cambridge, Dept Vet Med, Cambridge CB3 0ES, England