1. Department of Physiology, Seoul National University College of Medicine, Seoul, Korea;
2. Ischemic/Hypoxic Disease Institute, Seoul National University College of Medicine, Seoul, Korea;
3. Department of Anesthesiology-Pain Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Suwon, Korea; and
4. Department of Oral Biology, Yonsei University College of Dentistry, Seoul, Korea