Fig. 220.127.116.11. Two and three consecutive serial sections containing smooth endoplasmic reticulum enveloping the microtubules (thick arrows). D – dendrite; S – dendritic spine; thin arrows– endocytosis in an terminal axon as an example of recirculation of synaptic vesicles. Scale = 200 nm. (Rat, hippocampal stratum radiatum). Download the high resolution image.