Fig. 5.

In 20-d-old neurons, some synaptic F-actin is exceedingly stable. Most F-actin is depolymerized in 24 hr (A). However, even at 24 hr, some F-actin clusters remain (A). Synaptophysin (syn) labeling (B) of the same neurons shown in A is unaltered by the treatment.Boxed regions are shown at higher magnification ininsets and illustrate that many of the most stable F-actin puncta are codistributed with synaptophysin puncta (arrowheads). con, Control; lat A, latrunculin A. Scale bar, 26.9 μm; insets, 10.8 μm.