Fig. 4: MJF-14 PLA efficiently distinguishes PD patients from controls but does not discriminate between stage IV and stage VI PD in the anterior cingulate cortex.

a Representative images comparing MJF-14 PLA and MJF-14 IHC in the superficial (SGM) and deep (DGM) layers of the ACC from control, Braak stage IV, and Braak stage VI PD. Black arrows indicate neuronal PLA, blue arrows indicate glial and neuropil PLA signals, and arrowheads highlight deposit particles/LBs. Scale bar = 20 µm. b Quantification of the total PLA particle count per mm². The control group is significantly different from the two PD groups (p < 0.001). c Quantification of the total deposit particle count per mm² (detected by IHC). PD stage VI is significantly different from both controls (p < 0.001) and PD stage IV (p = 0.011). d Quantification of LB count per mm². PD stage VI is significantly different from both controls and PD stage IV (p < 0.001). Values plotted in (b–d) can be found in Suppl. Table 4. e Percentage of neurons containing PLA particles (averaged for SGM and DGM). Each subject is indicated as a dot. Both PD groups are significantly different from controls (p < 0.001), but not from each other (p = 0.409). For more information, see Suppl. Table 5. f Correlation between PLA particles and deposit particles (IHC) in PD stage VI. The density of PLA particles is inversely logarithmically correlated with the density of deposit particles (r_s [20] = −0.732, p < 0.001). g Correlation between deposit particles and LBs in PD stage VI. The density of LBs is positively correlated with the density of deposit particles (r_s [20] = 0.675, p = 0.001). h Schematic representation of image segmentation for analysis: PLA pathology is analysed inside neuronal cell bodies (in nuclei (purple) and/or assumed cytoplasm (grey)) as well as away from neuronal cell bodies (denoted neuropil, but also containing glia (pink)). i Quantification of the average PLA particle count per affected neuron in SGM, with each subject indicated as one dot. There are significantly more PLA particles in affected neurons of PD stage VI than controls (p = 0.011) and a similar non-significant tendency for PD stage IV (p = 0.218). j Quantification of the average PLA particle count per affected neuron in DGM, with each subject indicated as one dot. The control group is significantly different from both PD stage IV (p = 0.007) and stage VI (p = 0.011). Values plotted in (i, j) can be found in Supplementary Table 6. k Proportion of different types of neuronal pathology, gradient grey coded for unaffected, solely nuclear, solely cytoplasmic, or mixed nuclear and cytoplasmic types. Values used for generating the graphic can be found in Supplementary Table 7. Data are displayed as mean ± SEM, averaged for SGM and DGM unless otherwise indicated, and comparisons are made using univariate analyses covarying with age, sex and post-mortem delay. *p < 0.05, **p < 0.01, ***p < 0.001.