Figure 4. Rarely observed non-standard events.

Strips of fluo-3 fluorescence line-scan images from two distinct mouse skeletal muscle fibers depolarized by a 500 ms long pulse. A and C show the baseline corrected fluorescence images; the corresponding spatially averaged global F/F₀ signal is shown at the bottom. B and D show the corresponding filtered images. Fluorescence events suggesting RyR channels closure followed by re-opening were occasionally detected after (A, B) and during a depolarizing pulse (C, D). Such complex events were seen in 4 and 11 images, respectively, out of the total of 99 images where events were detected and analyzed.