[1] CLARKE INST PSYCHIAT,HUMAN BRAIN LAB,TORONTO M5T 1R8,ONTARIO,CANADA
[2] UNIV TORONTO,DEPT PSYCHIAT,TORONTO M5S 1A1,ONTARIO,CANADA
[3] UNIV TORONTO,DEPT PHARMACOL,TORONTO M5S 1A1,ONTARIO,CANADA
[4] VIENNA UNIV,INST BIOCHEM PHARMACOL,A-1010 VIENNA,AUSTRIA