1. The Calcium Signaling Group, Department of Biochemistry and Molecular Cell Biology, University Medical Centre Hamburg-Eppendorf, 20246 Hamburg, Germany.
2. Department of Computational Neuroscience, University Medical Centre Hamburg-Eppendorf, 20246 Hamburg, Germany.
3. Department of Pathology, New York University School of Medicine, New York, NY 10016, USA.
4. Microscopy Core Facility, University Medical Centre Hamburg-Eppendorf, 20246 Hamburg, Germany.
5. Organic Chemistry, University of Hamburg, 20146 Hamburg, Germany.
6. Institute of Neuroimmunology, University of Göttingen, 37075 Göttingen, Germany.
7. Department of Biology, University of Pennsylvania, Philadelphia, PA 19104-6313, USA.