Figure 3.

Gastrocnemius Muscle and NMJ Defects Are not Rescued in IV-Treated nmd Mice Compared to ICV-Treated Mice

(A) VVG-stained cross sections of gastrocnemius muscles of IV- and ICV-treated nmd males were examined at 8 weeks post-injection under 40× magnifications and compared with those of age-matched untreated nmd and healthy control mice (n = 4 for each group). (B) The area size of muscle fiber in IV-treated nmd mice is similar to untreated mice and significantly reduced compared to ICV-treated mice (one-way ANOVA, IV versus ICV, p < 0.001). (C) The intensity of interstitial and periarterial fibrosis is significantly higher in the muscles of IV-treated nmd mice compared to ICV-treated (one way ANOVA p < 0.01) and unaffected control mice (one-way ANOVA, p < 0.001). (D) NMJs from gastrocnemius muscle of IV- and ICV-treated males at 8 weeks of age compared to those of age-matched untreated and healthy control (n = 4 for each group). Muscles were labeled with α-BTX for acetylcholine receptors (AChRs), anti-neurofilament, and anti-vesicular acetylcholine transporter (VAChT) for nerve terminals. (E) Percentage of innervated, partially innervated, and denervated muscles; % of fully innervated in ICV-treated is ∼69% versus ∼7% in IV-treated mice (one-way ANOVA, p < 0.001). (F) Percentage of fragmented endplates in ICV-treated is ∼8% versus ∼96% in IV-treated mice (one-way ANOVA, p < 0.001). Scale bars, 50 μm. Error bars represent mean ± SEM. *p < 0.05 and ***p < 0.001.