Fig. 2: Ca2+-activated force and SHG multiphoton imaging simultaneously performed in single wt and mdx EDL muscle fibers.

Representative example recordings of force (top) and myosin SHG signals (bottom) from a single EDL fiber from a wt mouse (left) and an mdx mouse (right) during successive solution exchange for increasing Ca2+ concentrations (decreasing pCa). Brief positive force spikes represent the time points of manual solution exchange performed several times per pCa step. Scale bar: 20 µm. CAS: cosine angle sum (a.u.). VD: vernier density (#/100 µm2)