1. Max-Planck-Institute of Biophysical Chemistry, Department of Neurobiology, Göttingen, Germany
2. Department of Biology, University of Ljubljana, Ljubljana, Slovenia
3. European Neuroscience Institute, Göttingen, Germany
4. Institute for Medical Microbiology and Hygiene, Johannes-Gutenberg-University, Mainz, Germany
5. Max-Planck-Institute of Biophysical Chemistry, Department of Cellular Biochemistry, Göttingen, Germany