1. Department of Anatomy and Neurobiology, Graduate School of Medicine, Osaka City University, Osaka, Japan
2. Department of Orthopaedic surgery, Nishinomiya Municipal Central Hospital, Nishinomiya, Japan
3. Department of Orthopaedic surgery, Graduate School of Medicine, Osaka University, Suita, Japan
4. Department of Degenerative Neurological Diseases, National Institute of Neuroscience, NCNP, Kodaira, Japan