Fig. 5. MAG-induced apoptotic activity leads to decreased neurite outgrowth of postnatal developing CGNs.
a–c Representative images and quantification (b, c) of P7 p75NTR+/+ and p75NTR−/− CGNs cultured for 24 h in medium containing 25 μg/ml Fc fragment (control) or 25 μg/ml MAG-Fc (total of 150 images per genotype and condition). The cells were labelled with anti-β III tubulin. Scale bars, 20 μm. The mean length of the longest neurite (b) and the percentage of neurons bearing neurites (c) are shown as mean ± s.e.m. of data from three separate cultures, ***p < 0.001 compared to control, two-way ANOVA followed by Bonferroni post hoc test. d Images of representative wildtype CGNs cultured for 24 h in medium containing 25 μg/ml Fc fragment (control) or 25 μg/ml MAG-Fc (images selected from 60 images per condition). The cells were triple-labelled with anti-cleaved casp-3, anti-β III tubulin and DAPI. Arrows show examples of neurite-less CGNs that are also double-positive for cleaved casp-3 and β III tubulin. Arrowheads show examples of β III tubulin positive and cleaved casp-3 negative CGNs with extended neurites. Scale bars, 50 μm. e–g Representative micrographs (e) and quantification (f, g) of wild type CGNs cultured for 24 h in medium containing no factors (control), 25 μg/ml MAG-Fc alone, 10 μM caspase 3 inhibitor (Z-DEVD-FMK) alone or MAG-Fc plus Z-DEVD-FMK. The cells were labelled with anti-β III tubulin. Scale bars, 50 μm. The mean length of the longest neurite (f) and the percentage of neurons bearing neurites (g) are shown as mean ± s.e.m. of data from three separate cultures (total of 150 images per genotype and condition), **p < 0.01 and ***P < 0.001 compared to control, two-way ANOVA followed by Bonferroni post hoc test