[1] KYOTO UNIV,FAC MED,DEPT MOLEC GENET,KYOTO 606,JAPAN
[2] KANAZAWA UNIV,SCH MED,NEUROINFORMAT RES INST,DEPT BIOPHYS,KANAZAWA,ISHIKAWA 920,JAPAN
[3] MAX PLANCK INST BIOPHYS CHEM,D-3400 GOTTINGEN,FED REP GER
[4] ECOLE NORM SUPER,NEUROBIOL LAB,F-75230 PARIS 05,FRANCE