Fig. 2

Correlative AV-1451 autoradiography (ARG) and immunohistochemical (IHC) findings assessing tau maturity, atypical AD and AD tauopathies. (A-C) Case 2 - Normal, (D-F) Case 5 – Pathological aging, (G-I) Case 6 – Hippocampal sparing (HpSp) Alzheimer’s disease (AD), (J-L) Case 10 – Primary Age-Related Tauopathy (PART), (M-O) Case 12 – Neurofibrillary tangle (NFT) predominant dementia. Columns from left to right show AV-1451 ARG, AV-1451 Blocked ARG (BLK-ARG, shown with “letter”*), PHF-1 and CP13 immunohistochemistry in the posterior hippocampal region in cases with various Braak neurofibrillary tangle stages (0-VI) and Thal amyloid phase (0-5). AV-1451 displaceable correspondence with IHC in the medial parahippocampal gyrus (green arrows) is strong with a trend for poorer AV-1451 signal correlation in the lateral parahippocampal gyrus (red arrows) seen especially relative to CP13 except in the hippocampal sparring AD case (G-I). The greatest AV-1451 and IHC concordance was observed in the occiptiotemporal gyrus in AD HpSp (case 6, green arrowhead). There is minimal-moderate AV-1451 signal in the hippocampal formation (CA1, green dashed arrows) that is modest relative to IHC in most samples, again especially as compared to CP13. In the Braak VI AD HpSp case (G-I, case 6), there is minimal AV-1451 signal in the medial parahippocampal gyrus (red dashed arrows) and minimal binding in the hippocampus (green dashed arrows) that is a mismatch to the PHF-1 and CP13. More muted AV-1451 signal was seen in the subiculum in PART (J-K, case 10, blue dashed arrows). Lateral geniculate AV-1451 diffuse, displaceable, minimal signal was seen in many cases (blue arrowheads) and some focal intense signal in some cases (case 10) that may represent vascular non-specific AV-1451 signal. Scale bar for all full size hippocampus at 5 mm, and for 20x zoomed insets at 25 μm. Black arrowheads indicate 20x inset locations