[1] NAGOYA UNIV,DEPT PHARMACOL,NAGOYA,AICHI 466,JAPAN
[2] KYORIN UNIV,DEPT NEUROSURG,MITAKA,TOKYO 181,JAPAN
[3] KYOTO UNIV,DEPT NEUROSURG,KYOTO 606,JAPAN
[4] SHINSHU UNIV,DEPT NEUROSURG,MATSUMOTO,NAGANO 390,JAPAN
[5] HAMAMATSU MED COLL,DEPT PHARMACOL,HAMAMATSU,JAPAN
[6] UNIV TOKYO,DEPT NEUROSURG,TOKYO 113,JAPAN