Figure 5.

DMH‐specific knockdown of Sirt1 (shRNA‐Sirt1, b, d–f, h) in 3‐month‐old WT mice results in a more aged NMJ morphology compared to age‐matched, control‐injected mice (shRNA‐Ctr, a, c, g). Representative low magnification images of whole mount sternomastoid muscle show tSC abnormalities (less staining intensity and fewer numbers) in shRNA‐Sirt1 mice (b, e, f). Note also tSC anomalies (arrows): large and intensely stained tSC bodies (d), tSCs migrated outside of NMJ area (e), or lightly stained with few processes colocalized with AChRs (f) in shRNA‐Sirt1 mice. Less severe changes are observed for nerve terminals (h, arrows), and almost no changes are seen in motor endplates (b, d–f). S100 Ab (for tSCs, green), NF200 Ab (for neurofilaments, green), BTX (for AChRs, red), and DAPI (nuclear staining, blue). Scale bar = 20 μm