Figure 7.

The tubular structure identified here was not a mitochondrion. Neurons were transfected with adenovirus vectors carrying GAP-43–GFP chimeric DNA after 3 h in culture and were observed using a confocal laser scan microscope 40 h later. 15 min before observation Mitotracker was added to the medium for vital staining of mitochondria. The medium was changed just before observation. The axon was observed in both FITC mode and Texas red mode simultaneously, and the movements of both GAP-43 transporting vesicles (a and c) and mitochondria (b and d) were recorded. a–d are the simultaneous double labeling, and interval between a and b and c and d is 17.25 s. The upper side is proximal to the cell body. The central area of the axon was photobleached before observation. Note that transporting vesicles cannot be identified in the peripheral area of the axon because of the high level of background staining. The GAP-43–containing vesicles identified in the central area were transported from the peripheral area during observation. Most of the mitochondria were stationary and only a few moved into the central region (arrows). Bar, 5 μm.