1. Department of Biology (A.K., K.Y., S.K.), School of Education, Waseda University, Nishiwaseda, Tokyo 169-8050, Japan
2. Laboratory of Brain Science (K.U., H.T., K.T.), Faculty of Integrated Arts and Sciences, Hiroshima University, Higashi-Hiroshima 739-8521, Japan
3. Core Research for Evolutional Science and Technology (K.U., H.T., K.T.), Japan Science and Technology Corporation, Tokyo 150-0002, Japan
4. Instrument Center for Chemical Analysis (S.O.), Hiroshima University, Higashi-Hiroshima 739-8526, Japan