Figure 2.

Salbutamol treatment improves postsynaptic NMJ morphology in ColQ^−/− mice. A. Representative confocal micrographs of NMJs in the lumbrical muscles of 10-wk-old WT, water treated ColQ^−/− (ColQ^−/− WFI) and salbutamol treated ColQ^−/− (ColQ^−/− SAL) mice, labelled with anti-neurofilament (red) and anti-synaptophysin (red, both NT) and Alexa fluor 488 α-bungarotoxin (green, AChR). Water treated ColQ^−/− mice display variable NMJ morphology with smaller NMJs with reduced AChR density. Scale bar, 10 μm. B. Quantitative analysis of presynaptic variables from lumbrical muscles. ColQ^−/− mice exhibited smaller nerve terminals with thinner axons, and these variables were unchanged in salbutamol treated mutants. C. Quantitative analysis of postsynaptic variables from lumbrical muscles. Water treated ColQ^−/− mice had reduced AChR area and compactness, which were significantly increased in salbutamol treated ColQ^−/− mice compared to water treated ColQ^−/− mice. D. Quantitative analysis of area of synaptic contact. ColQ^−/− mice have significantly reduced area of synaptic contact which is increased by salbutamol treatment but remains smaller than in WT animals. E. Quantitative analysis of fragmentation of NMJs. ColQ^−/− NMJs exhibit significantly increased number of AChR rich fragments per NMJ, and this was not different in salbutamol treated animals. n = 180 NMJs analysed per group for B-E. Analysis of NMJ-morph variables from soleus muscle are provided in Supplementary Material, Figure S2. F. Quantification of α-bungarotoxin fluorescence intensity of individual NMJs measured from projection of confocal stacks from lumbrical muscles. Fluorescence intensity was significantly decreased in water treated ColQ^−/− mice, and was significantly increased in salbutamol treated ColQ^−/− mice compared to water treated ColQ^−/− mice. n = 120 NMJs analysed per group for F. All error bars depict S.D. Unpaired Student’s t tests. ^∗∗∗∗p < 0.0001, ^∗∗∗p < 0.001, ^∗∗p < 0.01, ^∗p < 0.05.