1. Department of Neurology and Neurological Science, Tokyo Medical and Dental University Graduate School of Medical and Dental Sciences, Yushima Bunkyo-ku, Tokyo, Japan
2. Laboratory of Comparative Pathology, Hokkaido University, Graduate School of Veterinary Medicine, Kita-ku, Sapporo, Hokkaido, Japan
3. Department of Neurology and Neurobiology of Aging, Kanazawa University Graduate School of Medical Science, Kanazawa, Japan
4. Department of Neurological Science, Tohoku University Graduate School of Medicine, Sendai, Japan
5. National Center of Neurology and Psychiatry, Tokyo, Japan