Fig. 7: ApoE deficiency reduces developmental dendritic spine formation and alters dendritic branching on layer V cortical pyramidal neurons.

Representative image of VGluT1 and PSD95 staining in cortical neuronal cultures (a) and quantification of VGluT1 (b) and PSD95 density (c) on neurites following ACM treatment. Control cortical neurons (i) and neurite (iv), cortical neurons (ii) and dendrite (v) treated with WT ACM, and cortical neurons (iii) and dendrite (vi) treated with ApoE KO ACM; Scale bar: 20 μm (i–iii) and 10 μm (iv–vi); n = 16 neurons (8 neurons/replicate, 2 biological replicates)/group; Representative confocal and Imaris images of apical (d) and basal (e) dendrites and spines of layer V pyramidal neurons from motor cortex of Thy1-YFP⁺ and Thy1-YFP⁺ApoE^−/− mice (P30). Dendrites and spines were traced and quantified in Imaris. Scale bars: 10 μm; Quantification of apical (f) and basal (g) dendrites of layer V pyramidal neurons from motor cortex of Thy1-YFP⁺ and Thy1-YFP⁺ApoE^−/− mice (P30). n = 5 mice/group; Representative neuron image (h) and 3D Sholl analysis (i) of layer V pyramidal neurons from motor cortex of Thy1-YFP⁺ and Thy1-YFP⁺ApoE^−/− mice. Scale bar: 20 μm; n = 5 mice/group; Representative images (j) and quantification (k) of CM-DiI-labeled CST axons in the spinal cord of WT (i) and ApoE KO (ii) mice. Orange arrows indicate the pyramidal decussation; yellow lines indicate the beginning and ending points for the CST axon length measurement; Scale bar: 1 mm; n = 8 mice for WT and 9 mice for ApoE KO; p value in (f, g, k) determined by two-tailed t-test; p values in (b, c) determined using the one-way ANOVA followed by a Tukey post hoc test; p values in (i) determined using the multiple t-test. Data are presented as mean values ± SEM.