1. Department of Veterinary Pharmacology; University of Tokyo; Tokyo 113-8657 Japan
2. Laboratory of Pharmacology; Faculty of Pharmaceutical Sciences, Josai International University; Chiba 283-8555 Japan
3. Division of Anatomy and Neuroscience; Department of Morphological and Physiological Sciences; University of Fukui Faculty of Medical Sciences; Fukui 910-1193 Japan
4. Department of Neuroscience and Cell Biology; Osaka University Graduate School of Medicine; Osaka 565-0871 Japan
5. Department of Animal Radiology; University of Tokyo; Tokyo 113-8657 Japan
6. Research Center for Food Safety, Graduate School of Agriculture and Life Sciences; University of Tokyo; Tokyo 113-8657 Japan