Fig. 11.

Venn diagrams showing the percentage of spines that contained SER, an endosomal compartment (coated pit, coated vesicle, large vesicle, tubular endosome, or MVB–tubule complex), or small vesicles at each age. The overlap areas show the percentages of spines with more than one type of compartment. The percentages under the labels give the overall proportion of spines containing a particular type of compartment. Thus, 19.8% of adult spines contained SER, whereas 1% of adult spines contained SER, endosomes, and small vesicles.