1. Stroke Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health (NINDS/NIH), Bethesda, MD, USA
2. Department of Clinical Neurosciences, Division of Stem Cell Neurobiology, Wellcome Trust-Medical Research Council Stem Cell Institute, University of Cambridge, Cambridge, UK
3. Department of Anesthesiology, Duke University Medical Center, Durham, NC, USA
4. Department of Neurobiology, Duke University Medical Center, Durham, NC, USA