1. L. Toro, M. Wallner, and P. Meera are in the Dept. of Anesthesiology at the University of California at Los Angeles School of Medicine, Los Angeles, CA 90095–1778, USA. Y. Tanaka is in the Dept. of Pharmacology, School of Pharmaceutical Sciences, Toho University, 2-2-1 Miyama, Funabashi-City, Chiba 274, Japan.