1. Department of Anatomy and Neuroscience, Hyogo College of Medicine, 1–1 Mukogawa-cho, Nishinomiya, Hyogo 663-8501, Japan
2. Pain Research Center, Kansai University of Health Sciences, 2-11-1 Wakaba Kumatori-cho, Osaka 590-0482, Japan
3. Department of Orthopedic Surgery, Wakayama Medical University, 811–1 Mimiidera, Wakayama 641-8510, Japan