1. Department of Neurophysiology, National Institute of Neuroscience (NIN), National Center for Neurology and Psychiatry (NCNP), 4-1-1 Ogawa-Higashi, Kodaira, Tokyo 187-8502, Japan
2. Present Address: Assisted Reproductive Technology (ART) Center, Okayama University, 1-1-1 Tsushima-Naka, Okayama 700-8530, Japan
3. Present Address: Animal Research Center, Tokyo Medical University, 6-1-1 Shinjuku, Shinjuku-ku, Tokyo 160-8402, Japan