1. Paul Flechsig Institute for Brain Research, Faculty of Medicine; University of Leipzig; 04103 Leipzig Germany
2. Institute of Biology, Faculty of Biology, Pharmacy and Psychology; University of Leipzig; 04103 Leipzig Germany
3. Institute of Anatomy, Histology and Embryology, Faculty of Veterinary Medicine; University of Leipzig; 04103 Leipzig Germany
4. Leibniz Institute for Neurobiology; 39118 Magdeburg Germany
5. Department of Neuroscience and Physiology; State University of New York Upstate Medical University; Syracuse NY 13210 USA