1. Department of Anatomy and Neurobiology; Kyoto Prefectural University of Medicine; Kawaramachi-Hirokoji Kamigyo-ku Kyoto 602-8566 Japan
2. Ushimado Marine Institute, Graduate School of Natural Science and Technology; Okayama University; Ushimado Setouchi Okayama 701-4303 Japan
3. Kansai College of Health Science; Kinmitsucho Ashiya Hyogo 659-0065 Japan