C. Representative images of semithin section analysis of sciatic nerves at P45 from Pmp22+/- saline and Pmp22+/- Niaspan-treated mice. Niaspan was administered daily by i.p. injection at 160mg/Kg starting at P15 for 30 days.C'. The percentage of tomacula in sciatic nerves was assessed by ultrastructural analysis, results are mean ± SEM, n= 6 animals per condition, p=0.0022, two-tailed Mann Whitney U test, representative of two independent experiments.D. G-ratio analysis on semithin sections of sciatic nerves shows that increased myelin thickness in Pmp22+/- sciatic nerves at P45 is restored to normal values following Niaspan treatment. Mean g-ratio values, WT saline-treated: 0.69 ± 0.002, 2052 fibers, n=5 animals; Pmp22+/- saline-treated: 0.66 ± 0.003, 2643 fibers, n=6 animals; Pmp22+/- Niaspan-treated, 0.68 ± 0.002, 2311 fibers, n=6 animals. WT saline as compared to Pmp22+/- saline-treated, p<0.0001; Pmp22+/- saline-treated as compared to Pmp22+/- Niaspan-treated, p=0.0002; Pmp22+/- Niaspan-treated as compared to WT saline, p=0.0899; repeated measures ANOVA.E. The number of myelinated fibers is similar between the 3 groups analyzed, p=0.4362, nonparametric one-way ANOVA, followed by Dunn's post hoc test. 