Fig. 4

Inverse correlation between synaptophysin or SV2A and NfL density. Correlation of NfL immunoreactivity with (A) synaptophysin and (B) SV2A density are shown per group in regions affected at Braak 4, 5 and 6. Heat-maps are color-coded for correlation coefficient (r), being blues representative of negative correlations and reds of positive correlations. For each correlation, the correlation coefficient is reported, together with its p-value. For the correlations highlighted with a square we are also reporting the scatterplots, color-coded for brain area (every data point represents one averaged measurement per layer III and V-VI). Linear mixed model p-values are adjusted for multiple testing (12 correlations per synaptic marker) *p < 0.05, **p < 0.01, ***p < 0.001 after Bonferroni method. Legend: DLB: Dementia with Lewy bodies; ENTC: entorhinal cortex; FusG: fusiform gyrus; GFS: superior frontal gyrus; NfL: neurofilament light chain; PCC: posterior cingulate cortex; PD: Parkinson’s disease; PDD: Parkinson’s disease dementia; PHG: parahippocampal gyrus