Figure 5.

The error in the release probability due to diffusion as a function of the peak calcium concentration and the release probability for model A (A and B) and model B (C and D). The signal-to-noise of the local calcium concentration is plotted as a function of the peak calcium concentration for two different sensor locations in (E). This SNR scales as $\sqrt{[{\text{Ca}}^{2+}]}$, which is the scaling of the solid line.