A. β2-nAChR availability (VT/fP) before (shaded bars) and after (solid bars) physostigmine injection for each subject. Thalamus: Percent displacement of 5-IA for subjects 1–6 were −7%, −22%, −14%, −22%, −35%, −0%, respectively. Striatum: Percent displacement of 5-IA for subjects 1–6 was −8%, −20%, −18%, −20%, −25%, −4%, respectively. Cortex: Percent displacement of 5-IA for subjects 1–6 were −9%, −25%, −18%, −26%, −30%, −2%, respectively. Cerebellum: Percent displacement of 5-IA for subjects 1–6 was −12%, −20%, −18%, −23%, −28%, 0%, respectively. B. Specific radioligand binding (Vs/fP) before (shaded bars) and after (solid bars) physostigmine injection for each subject. Thalamus: Percent displacement of 5-IA for subjects 1–6 were −8%, −25%, −17%, −25%, −41%, 0%, respectively. Striatum: Percent displacement of 5-IA for subjects 1–6 was −10%, −27%, −24%, −26%, −34%, +5%, respectively. Cortex: Percent displacement of 5-IA for subjects 1–6 were −13%, −40%, −29%, −36%, −50%, −6%, respectively. Cerebellum: Percent displacement of 5-IA for subjects 1–6 was −17%, −90%, − 35%, −32%, −40%, −1%, respectively.