Figure 3.

Spinules from thin spine heads into a neighboring axon or an astrocytic process. a, b, Serial sections though a small spinule (arrowhead; lavender) emerging from a thin spine head into a neighboring axon (n; green). In serial sections a-d, portions of a long spinule (arrow; purple) emerge from a thin spine head into an astrocytic process (as, light blue). e, Reconstruction of the small spinule (lavender) from the thin spine neck into the neighboring axon (green) as illustrated in a and b; postsynaptic density on the spine is red. f, Reconstruction of a thin spine with long spinule emerging from its head (purple) into an astrocytic process (light blue) as illustrated in a-d.