[1] Kagawa Univ, Fac Med, Dept Gastroenterol & Neurol, Takamatsu, Kagawa 760, Japan
[2] Sci & Technol Res Ctr Inc, Mitsubishi Chem Grp, Yokohama, Kanagawa, Japan
[3] Natl Inst Nat Sci, Natl Inst Physiol Sci, Div Neurol & Bioinformat, Okazaki, Aichi 4448585, Japan
[4] Kagawa Univ, Fac Med, Dept Gastroenterol Surg, Takamatsu, Kagawa 760, Japan