1. Department of Biomedicine, University of Basel, CH-4056 Basel, Switzerland
2. Department of Cell Biology, Erasmus Medical Center, 3015 GE Rotterdam, Netherlands
3. Department of Molecular, Cellular, and Developmental Biology and Program in Neuroscience, University of Michigan, Ann Arbor, MI 48109
4. Biomedical Imaging Group, Erasmus Medical Center, 3015 GE Rotterdam, Netherlands