[1] UNIV MESSINA,INST NEUROL,I-98100 MESSINA,ITALY
[2] UNIV PAVIA,DEPT INTERNAL MED & THERAPEUT,CLIN PHARMACOL UNIT,I-27100 PAVIA,ITALY
[3] NATL NEUROL INST C BESTA,MILAN,ITALY
[4] UNIV WALES COLL MED,DEPT PHARMACOL & THERAPEUT,CARDIFF CF4 4XN,S GLAM,WALES