Movie 1.

Overview of neuronal growth cone cryo-electron tomography data and segmentation. Overview of cryo-ET procedures used during this study. The video starts with a lowmagnification electron micrograph of a neuronal growth cone, with the cell membrane depicted in blue; the C-domain (C), transition zone (T) and peripheral domain (P) and ice contamination (I) indicated. A representative region over a hole in the carbon for tilt series data collection is indicated by the dashed cyan box. The video then shows the corresponding tilt series acquired for this region, with the peripheral leading edge of the growth cone indicated. Next, the corresponding reconstructed 2x binned tomogram is shown, followed by the corresponding semiautomated segmentation with features coloured as indicated.