Fig. 2

4-AP treatment shows potent axon protection using YFP-filled swellings to screen for damaged axons. A–B Thy1-YFP-16 mice were given vehicle (A) or 4-AP (B) treatment on days 1–7 after TBI. Confocal images of axons in the corpus callosum illustrate YFP (green) fluorescence accumulation in axonal swellings (white arrows), which is a sensitive indicator of axon damage. Adjacent YFP-positive axons have YFP diffusely distributed along normal appearing axons. C–D ImageJ particle analysis of YFP accumulation in axonal swellings. 4-AP treatment reduced the density (C) and the percent area occupied by axon swellings (D). Bars represent mean ± SEM with an individual data point shown for each mouse. Unpaired Student’s t-tests. See Fig. 1 for mouse sample numbers and Table 1 for statistical details