Fig. 1

NRG1 expression is reduced in severe SMA mice and patients A Schematic of NRG1 protein isoforms, Type I and Type III. B Relative NRG1-I and C NRG1-III mRNA expression levels in spinal cords of WT and SMA mice at P1 (n = 3 each). D Relative NRG1-I and E NRG1-III mRNA expression levels in spinal cords of controls and SMA Type 1 cases. F Representative L1 MNs stained with ChAT (blue) and NRG1 (white) in WT and SMA mice at P12 (scale bar: 50 μm). Quantification of NRG1 punctae on G L1 MNs, H L5 lateral motor column (LMC) MNs, and I L5 medial motor column (MMC) MNs from P2 WT and SMA mice (n = 3 each). J Representative LMC and MMC L5 MNs stained with ChAT (blue) and NRG1 (white) in WT and SMA mice at P12 (bottom scale bar: 100 μm and top scale bar: 20 μm.) Quantification of NRG1 punctae on K L1 MNs, L L5 LMC MNs, and M L5 MMC MNs in P12 WT and SMA mice (n = 3 each). N Representative confocal images of L1 VRs stained with NRG1 (red), Tuj1 (green), NFH (blue) in WT and SMA mice at P2 (scale bars: 10 μm and magnified scale bar: 1 μm). O Percentage of Tuj1 + overlap with NRG1 + over total Tuj1 + punctae of WT and SMA mice at P2 (n = 3 each) in L1 VRs and P DRs. Q Representative confocal images of human VRs stained with NRG1 (red), Tuj1 (green), P0 (blue) from CNTL 12-02 and SMA 11-01 (scale bar: 20 μm and magnified scale bar: 2.5 μm). R Percentage of Tuj1 + overlap with NRG1+ over total Tuj1 + punctae in VRs of controls and SMA Type 1 cases and S in DRs of controls and SMA Type 1 cases. Data represents means and SEM. Statistical analysis was performed using unpaired t test. Significance: *p \(\le\) .05, **p \(<\) 0.01