Fig. 2
From: Lessons learned about [F-18]-AV-1451 off-target binding from an autopsy-confirmed Parkinson’s case
Coronal in vivo [F-18]-AV-1451 PET images superimposed to brain MRI (a, left), matching autopsy tissue blocks (a, right), phosphor screen autoradiography (b), and microphotographs of nuclear emulsion dipped slides after incubation with [F-18]-AV-1451 (c) from the PD subject. The numbers displayed on PET and autoradiography images correspond to matching ROIs. Most ROIs analyzed did not exhibit detectable autoradiography signal, with the exception of the EC (red asterisk) (#10, reflecting Braak II age-related NFT pathology), leptomeningeal melanocytes adjacent to the lateral ventricle (red asterisk) (#12), and the mesencephalus (red and black asterisks) (#18, reflecting off-target binding to neuromelanin-containing neurons in the substantia nigra and meningeal melanocytes, respectively). The choroid plexus (red asterisk) (#14) displayed a very faint autoradiography signal that was not blocked with 1 μM unlabeled AV-1451. Numbers correspond to the following anatomical regions: #1 = middle frontal, #2 = putamen and pallidum, #3 = inferior temporal, #4 = anterior cingulate, #5 = superior frontal, #6 = middle frontal, #7 = inferior frontal, #8 = superior temporal, #9 = inferior temporal, #10 = HPC/EC, #11 = putamen and pallidum, #12 = thalamus, #13 = caudate, #14 = choroid plexus, #15 = middle frontal, #16 = occipital, #17 = cerebellar cortex and dentate nucleus, and #18 = substantia nigra. Abbreviations: EC = entorhinal cortex, HPC = hippocampus; MRI = magnetic resonance imaging; NFT = neurofibrillary tangle; PD = Parkinson’s disease; PET = positron emission tomography; ROI = region of interest. Scale bar = 1 cm (b), 20 μm (c)