Figure 1

Fig. 1. Anterograde movement of photobleached MTs in elongating Xenopus neurite growing on laminin-coated substrate. (A-D) Fluorescent images of a neurite captured after photobleaching. The photobleaching was performed 16 hours after cell culture preparation. The bleached segment was at the distal (near the growth cone) axonal segment. Numbers indicate time in minutes:seconds after photobleaching pulse. The position of the center of the bleached zone is indicated by arrows. The photobleached zone remained visible for about 6 min. Forward movement of the photobleached zone was clearly visible during the first few minutes after photobleaching. The rate of bleached zone movement was about 48 µm/min and the rate of growth cone advance was about 85 µm/min. (E) Fluorescence intensity profiles of axonal segment including photobleached segment created from images A (15 s after photobleaching, open circles) and C (8 min 15 s after photobleaching, filled squares). The bottom of the fluorescence intensity profile (arrows) moved towards the distal end of the neurite. Bars, 10 µm.