MAPT and supranuclear palsy, progressive, 1: Regression coefficients for the effects of neuronal and glial tau burden on DTI metrics are displayed in Fig. 3 (all estimates, confidence intervals and P-values are shown in Supplementary Tables 4 and 5). A relationship was observed between FA and neuronal tau in the motor cortex in PSP-RS (Supplementary Fig. 1), with a one-unit increase in neuronal tau burden associated with a ∼8% decrease in FA in PSP-RS.