Fig. 2

Rutin protects neuronal morphology from toxic tau oligomers and promotes microglial engulfment of extracellular tau. A Immunolabeling of MAP2 (green) in primary neuronal cultures treated with 1 μM tau oligomers in the presence or absence of 8 μM rutin for 24 h (scale bar: white, 25 μm; red, 10 μm). B The concentric rings spaced 20 μm apart centered on the soma center, which was used to count the number of intersections for the Sholl analysis. Scale bar: 40 μm. C Sholl analysis of the dendritic branching in primary neuronal cultures treated with 1 μM tau oligomers in the presence or absence of 8 μM rutin for 24 h. Forty neurons per culture from three independent cultures were used for the analysis. D Immunolabeling of tau (green) within Iba-1⁺ (red) cell in primary microglial cultures treated with 1 μM tau oligomers in the presence or absence of 8 μM rutin for 24 h (scale bar: 10 μm). E Quantification of tau puncta engulfed by Iba-1⁺ microglial cells in D. At least 20 microglial cells per culture from three independent cultures were used for the analysis. Data represent means ± SEM and were analyzed by two-way ANOVA with Bonferroni’s test (C) or Student’s t test (E). ***P < 0.001