Figure 7

Microtubules and actin trails during fragmentation. (a) Intensity of microtubular α-tubulin and glu-α-tubulin in axonal shafts from control axons, or axons deprived for 24 hours at different stages of fragmentation. (b) Representative quantitative confocal images of glu-α-tubulin and F-actin (for reference) of control axons, or axons deprived for 24 hours which are unfragmented or fragmented. Scale bar: 10 μm. (c,d) Representative quantitative confocal images (c) and quantification (d) of tubulin variants, βII-spectrin and F-actin of control axons, or axons deprived for 18 hours. Microtubule preparations (MT prep.) were achieved by detergent-extraction during glutaraldehyde fixation. Values between brackets in (c) are the mean change compared to the NGF control condition. Scale bar: 10 μm. Data are represented as mean ± SEM. (e) Representative axonal segments with microtubules stained against α-tubulin and images with STED nanoscopy. Scale bar 1 µm. (f) intensity profile from the line showed in panel (e). Arrows point to intensity peaks evidencing individual microtubules along the axon. (g) Representative STED images from microtubules stained against total α-tubulin (top) or acetylated-α-tubulin (bottom). Arrows point to debris where microtubule staining does not evidence filamentous polymers. Scale bar 1 µm. (h,i) Representative STED images of phalloidin staining on fixation-extracted axons. Scale bar 1 µm.