Fig. 4. SN-6 and dynasore mitigate increased swelling of axonal varicosities following axonal strain injury.

a Experimental design. b Representative phase-contrast micrographs of axonal pathology following injury (15% strain) and vehicle (0.08% DMSO) or drug pretreatment. c Application of axonal stretch to control (vehicle treated) cultures induces the formation of large (twofold) focal axonal varicosities by 2 and 3 h post-injury. Axonal swellings continue to increase in size (threefold) through 6 h post-injury. Pretreatment with 80 μM dynasore or 10 μM SN-6 prior to stretch prevents injury-induced swelling of axonal varicosities at 3 and 6 h. d Strain injury induces a substantial increase in the number of varicosities at 3 and 6 h post-stretch in control cultures. Pretreatment with 80 μM dynasore prevents the increase in number of varicosities at 3 and 6 h post-injury. Pretreatment with SN-6 delays the increase in varicosity number until 6 h post-injury. Asterisk (*) and hash (#) indicate significant difference from respective condition’s pre-injury data. Results obtained from three independent experiments, (n = 3). ^#p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001 by two-way ANOVA followed by Bonferroni post-hoc test, 30–40 regions of interest (ROIs) were randomly chosen from three independent microfluidic device cultures (separate litter donor animals) per condition. Error bars are s.e.m. Scale bar, 50 μm