Plasma membrane topological changes become long lived in the presence of dynasore. Dynasore was added to the bathing solution at a final concentration of 80 µM at least 10 min before the imaging. (A) Long-lived increases in P/S and P+2S are observed after fusion of a granule (release of NPY-Cer). Circles are centered over the last observed location of the granule. Bar, 1 µm. (B) Data from A is presented with the vertical dotted line indicating the frame before fusion. (C) Schematic interpretation of the event in A. In the presence of dynasore, a fused structure is formed with significant indentation and curvature that is connected to the plasma membrane.