SYP and amyotrophic lateral sclerosis: Nevertheless, in the limb muscles the difference in the percentage of NMJs labeled with these two antibodies was statistically significant both when comparing ALS donors with adult (synaptophysin, p = 0.0004; S100B, p<0.0001) and ALS donors with elderly (synaptophysin, p = 0.0107; S100B, p = 0.0005) controls.