Fig. 3

NRG1-III overexpression accelerates several aspects of motor axon development in SMA mice A Representative EM images of L1 VRs in WT, WT NRG1-III + , SMA, and SMA NRG1-III + mice at P2 (scale bar: 1 μm). The black, green, yellow, and pink arrows indicate myelinated, segregated, ensheathed and abutting axons, respectively. B Quantification of total number of axons in L1 VRs of WT (n = 3), WT NRG1-III + (n = 3), SMA (n = 5), and SMA NRG1-III + (n = 4) mice at P2; separated by axon category for WT and WT NRG1-III + C and SMA and SMA NRG1-III + D mice. (E and F) Axon diameters and G-ratios of L1 VRs in WT and WT NRG1-III + E and SMA and SMA NRG1-III + F mice. G Percentage of axons by axon diameter for each genotype. H Percentage of axons by different G-ratio categories for SMA and SMA NRG1-III + mice. Data represents means and SEM. Statistical analysis was performed (B) and (H), using one-way ANOVA; in (C), (D) and (G) using unpaired t test. Significance of WT compared to SMA NRG1-III + and WT NRG1-III + compared to SMA not included. Significance: *p \(\le\) .05, **p \(<\) 0.01, ***p \(<\) 0.001