Fig. 4. Actin distribution in protruding and retracting veils. (A) Veil dynamics merge (left) and filamentous actin distribution (right) in a growth cone. The merge combines the last live phase-contrast image before extraction and the one obtained 6 seconds earlier. Enlarged insets (p, r) show regions of veil protrusion (red) and retraction (cyan). (B) Line scans of Texas Red phalloidin fluorescence for protrusion and retraction derived from the regions of the growth cone shown in A (dotted lines). Fluorescence was normalized to 100 at peak of protrusion distribution. Protruding veils have more and deeper filamentous actin than retracting veils. n=4 growth cones; 9 retracting veils; 22 protruding veils.