Fig. 11.

Selected panels from time-lapse video analysis demonstrating that astrocyte movements can have dynamic effects on neuron processes during astrocyte abandonment and cavity formation. An interval of 6 min separates each panel for a total recording time of 54 min. Panel 1 is a low-power view of an adult DRG neuron (arrow) with a process (boxedarea) that can be followed at higher power in panels 2–10. Note especially the astrocyte marked with an arrowhead and the bifurcated neurite marked with an arrow in panels 2and 3. As this astrocyte cavity gradually increases in size, the marked astrocyte is pulled and stretched to a very thin morphology, whereas the marked neurite is broken or pulled free from its original connection in panel 3 and is left to retract in panels 4–10. Note the retracting end of the neurite that is being reabsorbed in panels 9 and10 (arrows). This is a dramatic demonstration of the potential for neurite damage seen several times in our time-lapse analysis simply because of the physical processes of astrocyte movement and withdrawal. Scale bar, 40 μm.