Figure 2.

PTV pausing is qualitatively and quantitatively similar to STV pausing. (A) Time-lapse images of PTVs labeled with GFP-bassoon. Individual PTVs are tracked with red, yellow or blue arrows. Most PTVs paused, and pauses were of varied durations. Frames were collected at the indicated times. Scale bars: 5 μm. (B) Kymographs demonstrating the movements of PTVs in three axons. Individual PTVs paused repeatedly at the same site (top panel), and multiple PTVs paused at the same site (middle and bottom panels). Pausing of multiple PTVs at a given site occurred both sequentially (middle panel) and simultaneously (bottom panel). Individual vesicles are highlighted in different colors for visualization. Pause sites are outlined in orange. On the ordinate axis, one pixel corresponds to 10 s. (C,D) STVs (magenta) and PTVs (green) paused at similar frequencies (C) and for similar mean durations (D). Data represent the mean + standard error.