1. Department of Neurosurgery, Graduate School of Medicine, Graduate School of Medicine, Hokkaido University, Sapporo, Hokkaido, Japan.
2. Department of Neurological Cell Therapy, Hokkaido University Hospital, Graduate School of Medicine, Hokkaido University, Sapporo, Hokkaido, Japan.
3. Department of Hematology, Graduate School of Medicine, Graduate School of Medicine, Hokkaido University, Sapporo, Hokkaido, Japan.
4. Department of Anatomy and Embryology, Graduate School of Medicine, Hokkaido University, Sapporo, Hokkaido, Japan.