Figure 6.
Increased phosphorylation of myosin light chain (MLC) in synaptic puncta apposed to hypoglossal motoneurons (HMNs) preceding synapse loss. A. Immunoblots for phosphorylated‐MLC (p‐MLC), MLC and β‐actin (β‐act) performed from microdissected hypoglossal nuclei (HNs) of 2‐month‐old non‐transgenic and age‐matched hSOD1G93A mice. B. Table showing the average ratios for p‐MLC/MLC and p‐MLC/β‐act in arbitrary units (a.u.) obtained from transgenic mice, compared to control (wild‐type, WT) animals taken as 1. n = 3 Western blots from six animals per genotype. *P < 0.05, non‐parametric Mann–Whitney U‐test. C, D. Synaptophysin‐immunoreactive (syn‐ir) colocalizing with p‐MLC puncta (arrowheads) apposed to SMI32‐immunolabeled HMNs in non‐transgenic (C) and transgenic (D) mice at 2 months of age. Secondary antibodies were labeled with cyanines 2, 3 and 5 for immunolabeling of SMI32, p‐MLC and Syn, respectively. Scale bars, 10 µm.