Figure 3.

The striatal and extra-striatal TSPO distribution in the human brain. Autoradiograms show the total binding of 2 nM [³H]PBR28 (panel A) in the frontal cortex, striatum and substantia nigra regions of human brain sections. Nonspecific binding of the radiotracer was determined using adjacent tissue sections with 1 μM PK11195 to mask TSPO (panel B). [³H]Microscale standards (ranging from 0 to 36.3 nCi/mg) were also counted for the calibration of radioactivity (panel C). The following CNS anatomical regions are denoted: Frontal cortex (Fr); Putamen (Pu); Caudate (Cd); Nucleus accumbens (NAc); Thalamus (Th); Substantia nigra (SN); Red nucleus (RN). For autoradiograms: red indicates high, blue indicates medium and white indicates low binding activity. Adapted from Xu et al., 2019 [74].