1. Department of Neuroscience, University Medical Centre Groningen, University of Groningen, Groningen, the Netherlands
2. Department of Immunobiology, Biomedical Primate Research Centre, Rijswijk, The Netherlands
3. Department of Cell Biology, University Medical Centre Groningen, University of Groningen, Groningen, The Netherlands
4. Department of Neuropathology, University Medical Centre Göttingen, Göttingen, Germany