Fig. 4

Statistical analysis shows amine responses significantly different from ATP responses. Calcium responses were measured for cells responding to the amine-mix (103 cells) and to ATP (269 cells). No overlap in cell populations was seen. Additionally, responses to high K⁺ (225 cells) were measured at the end of an experiment. Three kinetic parameters were quantified: Onset time, measured from onset of response to 50% of maximal peak height (a, time to 50%), peak width at half-maximal height (b, half width), and maximal peak height (c, peak height), expressed as ∆F/F₀. Distributions are shown as box plots, notches represent 95% confidence interval, outliers are shown as circles. Significance was estimated with two-tailed t-test, **p < 10^–10, ***p < 10^–15; ****p < 10^–30. Note that all three response characteristics are highly significantly different for amine vs. ATP responses