The time course of flux is different in frogs and mice. The black trace shows release flux in a WT mouse FDB cell, activated by the voltage clamp pulse represented at the top. The green trace shows a comparable record for a cell from frog semitendinosus muscle voltage clamped in a Vaseline gap. Records are scaled to match the levels reached after the early peak. Note in the mouse the more complex decay, described as a shoulder. Cells are in similar but not identical solutions designed to block ionic currents. Both internal solutions had 10 mM EGTA. The mouse cell was studied by Royer et al. (2008). The frog cell was studied by Rengifo et al. (2002).