1. Department of Biological Sciences, Tokyo Institute of Technology, 4259-B19 Nagatsuta-cho, Midori-ku, Yokohama 226-8501, Japan
2. Department of Physiology, Kitasato University School of Medicine, 1-15-1 Kitasato, Minami-ku, Sagamihara 252-0374, Japan
3. Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine, 200 First Street SW, Gug 9-21D, Rochester, MN 55905, U.S.A.
4. Department of Molecular Physiology, National Cerebral and Cardiovascular Center Research Institute, 5-7-1 Fujishiro-dai, Suita, Osaka 565-8565, Japan