Fig. 4

Analysis of axonal length and synapsin-1 expression. Left panel: axonal length in neurons derived from controls and patients. a, b Tuj-1b (red) + Dapi (blue); c–f Tau-1 (red) Tuj-1b (Green) Dapi (blue). Side insets show the 3D-trajectory of axons in IMARIS images. White arrows show axonal initial segments as well as axon distal segment; the asterix show truncated neurite. g Quantification of axonal length (µm) for Tau-1 positive neurons derived from controls and patients at 7 weeks of differentiation **p = 0.0064, t test, 2 tail. Right panel: expression of Synapsin—1 clusters in neurons derived from controls (h) and patients (i). The inset corresponding to the magnification of clusters are shown in lower panels. j Quantification of the synapsin − 1 clusters in BIII-tubulin positive cells (Tuj-1b) *p = 0.032, t test, 1 tail. k Arrangement of microfilaments by phalloidin staining. Bar scale. 20 microns