Representative time activity curves (TACs) and the reference region (RR) for the five considered radioligands: [11C]DASB ([11C]DASB), [11C]CUMI-101 ([11C]CUMI), [11C]6-OH-BTA-1, Pittsburgh Compound-B ([11C]BTA), [11C]ABP688 ([11C]ABP), and [11C]WAY-100635 ([11C]WAY). AMY, amygdala; CER, cerebellum; CIN, cingulate; DPU, dorsal putamen; GCER, gray-matter cerebellum; INS, insula; MED, medial prefrontal cortex; PCN, precuneus; PIP, parahippocampal gyrus; TEM, temporal; WCER, white CER.