[1] Osaka Univ, Grad Sch Med, Dept Anat & Neurosci, Suita, Osaka 5650871, Japan
[2] Asahikawa Med Coll, Dept Anat, Asahikawa, Hokkaido 0788510, Japan
[3] Duke Univ, Med Ctr, Div Neurol, Durham, NC 27710 USA
[4] Japan Sci & Technol, CREST, Tokyo, Japan