Figure 6.

The inhibition of p75^NTR-mediated RhoA/ROCK signaling protects from Aβ-induced morphological changes. The TAT-Pep5 peptide was added to primary hippocampal cultures (DIV 14) to inhibit p75^NTR–mediated intracellular RhoA activation and the Y-27632 inhibitor was applied to prevent ROCK activation. Some neuronal cultures were incubated with vehicle as control (nil). Subsequently, neuronal cultures were incubated with vehicle (Vehicle) or with 500 nM Aβ_1–42 oligomers (Aβ_1–42) for 6 h. (A) depicts representative dendritic segments of f-eGFP-transfected neurons treated as indicated (scale bar = 5 µm). The quantification of the effect of amyloid-β treatment on spine density (B), spine length (C), and spine head width (D) is shown in the graphs. Each column gives the mean value + SEM where the numbers indicate the analyzed neurons (N = 3). For statistical evaluation, a One-way ANOVA with Sidak post-test was used to compare the means of each of the control to the corresponding amyloid-β groups. P values as indicated or **** = p < 0.0001.