1. Department of Anesthesiology and Pain Medicine, Juntendo University Faculty of Medicine, Tokyo 113-8431, Japan.
2. Department of Cardiovascular Physiology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, 700-8558, Japan.
3. Department of Dental Anesthesiology, Faculty of Dental Science, Kyushu University, Fukuoka, 812-8582, Japan.
4. Department of Anesthesiology, Faculty of Medicine, The University of Tokyo, Tokyo, 113-8655, Japan.
5. Department of Anesthesiology and Pain Relief Center, JR Tokyo General Hospital, Tokyo, 151-8528, Japan.
6. First Department of Physiology, Kawasaki Medical School, Kurashiki, 701-0192, Japan.