1. Institute of Topographic Anatomy, Department of Pathobiology, University of Veterinary Medicine, 1210 Vienna, Austria
2. Institute of Anatomy, Anatomy and Cell Biology, Faculty of Medicine, University of Bonn, 53111 Bonn, Germany
3. Institute of Anatomy, Neuroanatomy, Faculty of Medicine, University of Bonn, 53111 Bonn, Germany
4. Institute of Pathology, Working Group Histology and Embryology, Department of Pathobiology, University of Veterinary Medicine, 1210 Vienna, Austria