[1] Juntendo Tokyo Koto Geriatr Med Ctr, Dept Neurol, Tokyo 1360075, Japan
[2] Univ & Postgrad Univ Juntendo, Fac Med, Dept Neurol, Tokyo, Japan
[3] Ctr Addict & Mental Hlth, Res Imaging Ctr, Human Brain Lab, Toronto, ON, Canada
[4] Univ Toronto, Dept Psychiat, Toronto, ON, Canada
[5] Univ Toronto, Dept Pharmacol, Toronto, ON, Canada