Fig. 3. Confocal fluorescence image of the unusually large, live axonal growth cone of a BODIPY/ceramide-labeled hippocampal neuron (24 hours in culture). The labeling protocol was as described for Fig. 2. (A) A merged image showing the BODIPY label recorded separately in the red (high concentration) and green (low concentration) channels. The many red puncta show Golgi-derived vesicles or vesicle clusters, whereas the green fluorescence outlines the growth cone's plasmalemma, labeled with small amounts of BODIPY. As soon as possible (30 seconds) after recording BODIPY fluorescence, a phase-contrast image was taken of the same growth cone and then superimposed on the red BODIPY image. The merged image shows the relationship of Golgi-derived vesicles to structures seen under phase contrast.