Endocytic uptake of α-synuclein PFFs is mediated by dynamin in ONS. ONS were pre-treated with 25 μmol/L D4a or 1 nmol/L Wort before incubation with 0.1 μmol/L α-synuclein PFF-488 for 4 h. (A) PFF-488 only; (B) D4a treatment; (C) Wort treatment; (D) scatterplot of intracellular PFF-488 puncta counts of 100 cells, n = 5 cell lines indicated by different shapes. Scale bar = 10 μm. Black/white shapes represent control ONS: circle = 1901, square = 1905, triangle = 1803, diamond = 1811, white circle with black border = 11401; Red shapes represent PD ONS: circle = 2803, square = 2810, triangle = 2505, diamond = 2818, circle with black border = 2820. Arrows to PFF-488-positive puncta. C: control. * P < 0.05; ** P < 0.01; *** P < 0.001