Figure 6.

Growth cone in mature hippocampus receives spinules from an axon. a, The lamellar junction (yellow) between two branch points shows numerous tubulo-vesicular components characteristic of growth cones. b-d, Serial sections through one of the spinules emerging from an axon (green) that has a coated tip on the cytoplasmic side of the growth cone invagination (d, arrow) and that is distinguished from a single membrane-coated vesicle (d, arrowhead). e, Reconstruction of the growth cone (yellow) and axon (green) that forms spinules with it. Scale bar in a applies to a-d.