[1] Univ Bristol, Sch Med Sci, MRC, Ctr Synap Plast,Dept Anat, Bristol BS8 1TD, Avon, England
[2] Univ Lausanne, Inst Biol Cellulaire & Morphol, CH-1005 Lausanne, Switzerland
[3] Hosp Sick Children, Toronto, ON M5G 1X8, Canada
[4] Novartis Pharma AG, Novartis Inst BioMed Res, Neurosci Res, CH-4002 Basel, Switzerland