(a) Representative EM images of lesions in the spinal cord of control (CT) and inducible conditional mutant (i-cMU) mice during remyelination at 14, 21 and 56 days post-lysolecithin injection (dpl). i-cMUs show persistently increased numbers of demyelinated axons (examples false colored in orange) compared to CTs up to 56 dpl. Scale bars: 3 μm. (b) Corresponding graphs with quantification of percentage of demyelinated axons within the remyelinated lesion area at 14, 21 and 56 dpl. Data points represent n = 3 mice for each, CT and i-cMU. The entire lesion area was quantified, at least 550 axons counted per animal (unpaired two-tailed two sample Student’s t-test; 14 dpl: i-cMU vs. CT, p=0.0263, t = 3.439; 21 dpl: i-cMU vs. CT, p=0.0086, t = 4.803; 56 dpl: i-cMU vs. CT, p=0.0127, t = 4.290), *p<0.05, **p<0.01. (c) g-ratio analysis of remyelinated fibers at 14, 21 and 56 dpl in i-cMU compared to CTs. Data points represent n = 3 mice for each, CT and i-cMU (unpaired two-tailed two sample Student’s t-test; 14 dpl: i-cMU vs. CT, p=0.1146, t = 2.011; 21 dpl: i-cMU vs. CT, p=0.3146, t = 1.149; 56 dpl: i-cMU vs. CT, p=0.1481, t = 1.789). (d) Linear correlation of g-ratio versus axon diameter in remyelinating lesions of i-cMU compared to CT mice, at 14, 21 and 56 dpl. At least 50 myelinated axons per mouse analyzed, n = 3 mice for each, CT and i-cMU. Bars represent mean ± SEM. CT = control, i-cMU = inducible conditional mutant, dpl = days post-lysolecithin injection.