1. Department of Aerospace Medical Research, Aerospace Medical Center, ROKAF (Republic of Korea Air Force), Cheongwon 363-842, Korea.
2. Department of Pharmacology, Institute of Natural Medicine, College of Medicine, Hallym University, Chuncheon 200-702, Korea.
3. Department of Anatomy and Neurobiology, and Institute of Neurodegeneration and Neuroregeneration, College of Medicine, Hallym University, Chuncheon 200-702, Korea.