1. Department of Preclinical Veterinary Sciences, University of Edinburgh, Edinburgh EH9 1QH, United Kingdom
2. Department of Biochemistry and Molecular Biology, Program in Cell Adhesion, Mount Sinai School of Medicine, New York, New York 10029
3. INSERM U-495, Biologie des Interactions Neurones/Glie, Hôpital de la Salpetrière, 75651 Paris Cedex 13, France