To view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 video Movie 4 Serial section sequence of the small axons shown in Figure 4 (7.3 MB TIFF file). The sections were 30 nm thick and imaged at 3 nm per pixel (Kasthuri et al., 2015). In this figure, the image resolution was reduced to 6 nm per pixel. Bar, 200 nm. Axonal endoplasmic reticulum is very narrow Mark Terasaki J Cell Sci 2018. 131:None-None; doi: 10.1242/jcs.210450 Download Original Video