Ablation of Myrf was induced in iCKO-Myrf mice with 5 days of once-daily tamoxifen i.p. injections, and starting 2 weeks later, mice were fed ad lib chow compounded with Sob-AM2 (84 μg/kg/d) or control chow. (A) Rotarod testing was performed weekly. (B) Summary analysis of rotarod data was performed by determining the week at which the mice crossed above a 60-second threshold for the remainder of the experiment. (C) Recovery was measured by dividing the average latency during the recovery phase (weeks 18–24) by the latency before decline (weeks 0–4). (D and E) Quantification of BlackGold images was performed by threshold analysis for white matter tracts (n = 7, 2 images per animal). Data points marked with orange indicate mice imaged by MRI (n = 3, 2 images per animal). (F) Group-average magnetization transfer ratio (MTR) maps from control and Sob-AM2 mice (n = 3) at week 24. Arrows indicate the body/isthmus of the corpus callosum, and arrowheads indicate lateral corpus callosum (orange for weak remyelination and white for strong remyelination). Scale bars: 1 mm. (G) BlackGold caudal brain images from representative control and Sob-AM2 mice imaged by MRI. Scale bars: 1 mm. Statistical significance was determined by a 2-tailed, unpaired t test comparing control to Sob-AM2 (*P ≤ 0.05, **P ≤ 0.01). In A, each t test was performed independently; green asterisks indicate weeks in which Sob-AM2 mice were significantly different from control Cre-positive mice (*P ≤ 0.05), and orange asterisks indicate weeks in which the Sob-AM2–treated mice were not significantly different from unaffected Cre-negative mice (*P > 0.10). All graphs show mean ± SEM.