1. Glial Cell Biology Lab, Achucarro Basque Center for Neuroscience, Zamudio, Bizkaia, Spain
2. Ikerbasque Foundation; Bilbao Bizkaia Spain
3. Department of Neuroscience, Faculty of Medicine, University of the Basque Country EHU/UPV, Leioa, Bizkaia, Spain
4. Instituto Cajal, CSIC; Madrid Spain
5. Department of Cell Biology, Histology and Pharmacology, Faculty of Medicine, University of Valladolid, Spain
6. Eberhard Karls University; Tübingen Germany
7. University of Valladolid; Valladolid Spain
8. Max Delbrück Center for Molecular Medicine in the Helmholtz Association; Berlin Germany.