Institute of Experimental Neurology, Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy; Cambridge Centre for Brain Repair and Cambridge Stem Cell Initiative, University of Cambridge, Cambridge, United Kingdom; Department of Veterinary Morphophysiology, Neuroscience Institute Cavalieri Ottolenghi, University of Turin, Turin, Italy; and Department of Neurobiology, The Weizmann Institute of Science, Rehovot, Israel (At 2011-10)