Fig. 6

Slow-twitch soleus shows moderate NMJ pathology in transgenic, but not in knock-in, model of SBMA. Pre-synaptic membranes of NMJs from soleus muscle were stained with synaptic vesicle marker synaptophysin and post-synaptic membranes were labeled with fluorescently tagged α-bungarotoxin (α-BTX; A). Transgenic mice showed a significant decrease in endplate area (B; p < 0.05), pre- and post-synaptic colocalization (D; p < 0.05), and post-synaptic complexity (E; p < 0.001). AChR compactness trended to an increase in transgenic mice, but this did not reach statistical significance (C). Knock-in mouse NMJs of the soleus did not show any significant changes in NMJ pathology compared to WT littermates (Additional File 1: Fig. S6). Mann–Whitney Test was used to evaluate statistical significance. NTg Non-transgenic; Tg Transgenic; WT Wild-type; KI Knock-in