Fig. 9.

Three-dimensional reconstructions of representative dendritic segments from each age. Endocytotic vesicles (coated pits, coated vesicles, and large vesicles) are shown inyellow. Tubular endosomes, MVBs, and MVB–tubule sorting complexes are red. These structures are infrequent along the length of the dendrites relative to the frequency of spines. Small vesicles (blue) are often located in spines but only occasionally colocalize with endosomes. Amorphous vesicles are shown indark brown. Scale bar, 1 μm.