1. Yamamoto Behavior Genes Project, ERATO (Exploratory Research for Advanced Technology), Japan Science and Technology Corporation (JST), and Mitsubishi Kasei Institute of Life Sciences, 11 Minamiooya, Machida, Tokyo 194, Japan
2. URA-CNRS 1491, Université Paris-Sud, Centre Scientifique d'Orsay, Bâtiment 446, 91405, Orsay, Cedex, France
3. Department of Physiology, Tokyo Women's Medical College, Kawada-cho, Shinjuku, Tokyo