Fig. 2

Intranasal IL-13 treatment enhances functional white matter integrity 35 days after tMCAO. A CAPs were recorded in the EC 35 days after tMCAO or sham operation Aa Diagram of the location of the stimulating and recording electrodes with 1 mm distance from the stimulus site to the recording site at the EC and the representative trace of the CAPs. Ab Comparison of peak-to-peak N1 an N2 amplitudes after various stimulation intensities n = 6–8/group. Ba Representative electron micrographs. The red arrows indicate myelinated axons, and blue arrows indicate unmyelinated axons. Scale bar: 5 μm. Scale bar = 20 μm for enlarged view. Bb, c Quantification of the number of total axons and the percentage of myelinated axons in electron micrographs n = 4–5/group. Bd Violin plot of the g-ratio, Be scatter plots of the g-ratio, and Bf frequency histogram of the g-ratio as a function of total axon diameter. Bg Comparison of g-ratio as a function of axon diameter. Quantification of myelinated axons and myelin thickness was done in five representative images/animals n = 1097 axons from 4 animals for Sham + Veh; n = 1089 axons from 4 animals for Sham + IL-13; n = 1345 axons from 5 animals for tMCAO + Veh; n = 1334 axons from 5 animals for tMCAO + IL-13 Ca Pearson correlation between the MBP/SMI32 immunostaining, and CAPs amplitudes at 1 mA stimulation intensity. n = 2–4/group. Cb Pearson correlation between the animals’ performance, CAPs amplitudes at 1 mA stimulation intensity, MBP/SMI32 immunostaining, and electron microscopy index n = 2–5/group. All data are presented as the mean ± SEM. *p ≤ 0.05, **p ≤ 0.01, ***p ≤ 0.001. Two-way ANOVA followed by Bonferroni’s post hoc (Ab, Bg), One-way ANOVA followed by Bonferroni’s post hoc (Bb, c), Kruskal–Wallis test followed by Dunn’s post hoc (Bd), and Pearson Correlation (C)