1. Pain & Neuroscience; Discovery Research Laboratory for Core Therapeutic Areas; Shionogi Co. Ltd.; 1-1 Futaba-cho 3-chome Toyonaka Osaka 561-0825 Japan
2. Laboratory of Chemical Pharmacology; Graduate School of Pharmaceutical Sciences; University of Tokyo; Bunkyo-ku Tokyo Japan
3. Center for Information and Neural Networks; Suita City Osaka Japan