[1] Kagawa Univ, Fac Med, Dept Neurobiol, Kita Ku, Kagawa 7610793, Japan
[2] Kagawa Univ, Fac Med, Dept Neurol Surg, Miki, Kagawa, Japan
[3] Kagawa Univ, Fac Med, Dept Ophthalmol, Miki, Kagawa, Japan
[4] Kawasaki Med Sch, Dept Physiol, Kurashiki, Okayama, Japan
[5] Univ Michigan, Dept Neurosurg, Ann Arbor, MI 48109 USA