Figure 4. The effect of unloading on nuclei number and atrophy of single muscle fibers studied by acute in vivo staining and imaging in live animals.

Fluorescent oligonucleotides were injected into single muscle fibers in EDL muscles at 0 and 14 days after unloading. (A) Representative images of single fibers. See legend of Figure 1 for details about image processing for the 2-dimensional illustrations. The number of nuclei (B) and the cross-sectional area (C) were calculated from image stacks. Horizontal lines indicate means; asterisk indicates statistical differences from normal values (*P = 0.03); scale bar: 25 μm.