Figure 3
Ca2+ transients in dysgenic myotubes transfected with fs-α1S. The confocal line-scan images in color show fluo-4 fluorescence across myotubes in response to a 50-ms depolarization from a holding potential of -40 mV to +30 mV (top) and +90 mV (bottom). Line scan images have a constant temporal dimension of 2.05 s (horizontal) and a variable spatial dimension (vertical) depending on the cell size. Traces immediately above each line scan show the time course of the fluorescence change in resting units (ΔF/Fo). Traces under lines cans show ICa2+ during the 50 ms depolarization used to stimulate the Ca2+ transient. The amplitude and the timing of the depolarization are indicated under each line scan. Note that fluorescence calibration bar is 1 ΔF/Fo. A 16-color calibration bar in ΔF/Fo units is included for visual reference.