Figure 3.

Microtubule destabilization and axon relaxation after dynamic stretch injury. A) Phase-contrast and fluorescence (fluo-4) photomicrographs demonstrating that axons without treatment (CSS) displayed multiple undulations after stretch and gradually resumed their original straight orientation within 40 min. However, axons pretreated with taxol (T; 1 μM) maintained their undulations for at least 3 h, while removal of taxol at 40 min poststretch allowed relaxation of axonal undulations by ∼3 h postinjury. In contrast, axons pretreated with nocodazole (N; 0.1 μM) relaxed to their prestretch orientation immediately after injury. Scale bars = 5 μm. B) Quantitative analysis of the length of individual undulations over time demonstrated that only pretreatment with taxol (1 μM) maintained the undulations, while a lower pretreatment dose (10 nM) or poststretch treatment (1 μM) had no effect. Values of data points are listed in Supplemental Table S1.