Double staining for NK-1R (a, d) and S100 (-subunit) (b, e). Merged images including DAPI reactions are shown in (c, f). Large nerve fascicles are seen. Sections are from gastrocnemius muscle specimen of the 6-week group, nonexercised side. There is NK-1R immunoreaction and to some extent an extra marked S-100beta immunoreaction in some regions (arrows) (a)–(f). For some regions there is NK-1R immunoreaction but not this type of marked S-100beta immunoreaction (arrowheads). Note that the nuclei within the nerve fascicles show a pink colour reaction whilst those located outside these show the characteristic blue DAPI reaction in (c, f). This means that the nuclei located inside the nerve fascicle exhibit the blue DAPI reaction merged with the colour reaction from the S-100beta staining. Bar = 25 μm.