[1] JOHNS HOPKINS UNIV,SCH MED,DEPT PSYCHIAT,BALTIMORE,MD 21205
[2] JOHNS HOPKINS UNIV,SCH MED,DEPT ANESTHESIOL & CRIT CARE,BALTIMORE,MD 21205
[3] JOHNS HOPKINS UNIV,SCH MED,DEPT NEUROSCI,BALTIMORE,MD 21205
[4] JOHNS HOPKINS MED INST,DIV NUCL MED,BALTIMORE,MD 21205
[5] JOHNS HOPKINS MED INST,DIV RADIAT HLTH SCI,BALTIMORE,MD 21205
[6] JOHNS HOPKINS UNIV,SCH MED,DIV NEURORADIOL,BALTIMORE,MD 21205
[7] UNIV COPENHAGEN,DEPT MED PHYSIOL A,DK-1168 COPENHAGEN K,DENMARK