1. Mitsubishi Kasei Institute of Life Sciences, 11 Minamiooya, Machida, Tokyo 194-8511 and Laboratory of Anatomy and Physiology, College of Bioresource Sciences, Nihon University, 1866 Kameino, Fujisawa, Kanagawa 252-8510, Japan
2. Laboratory of Anatomy and Physiology, College of Bioresource Sciences, Nihon University, 1866 Kameino, Fujisawa, Kanagawa 252-8510, Japan
3. Mitsubishi Kasei Institute of Life Sciences, 11 Minamiooya, Machida, Tokyo, Japan