Table 1.

Measured ${\text{Mg}}_{\text{o}}^{\text{2+}}$ IC₅₀ values

Voltage (mV)	${\text{Mg}}_{\text{o}}^{\text{2+}}$ IC50 140 ${\text{Na}}_{\text{o}}^{+}$/125 ${\text{Cs}}_{\text{i}}^{+}$ (μM)	${\text{Mg}}_{\text{o}}^{\text{2+}}$ IC50 140 ${\text{Na}}_{\text{o}}^{+}$/8 ${\text{Cs}}_{\text{i}}^{+}$ (μM)	${\text{Mg}}_{\text{o}}^{\text{2+}}$ IC50 70 ${\text{Na}}_{\text{o}}^{+}$/8 ${\text{Cs}}_{\text{i}}^{+}$ (μM)
−15	2390	208	132
−25	1180	70.3	63.2
−35	541	56.3	35.8
−45	232	30.8	19.4
−55	116	24.9	12.3
−65	55.5	12.1	7.06
−75	41.5	12.1	5.89
−85	17.2	6.55	3.72
−95	9.79	6.46	2.98
−105	4.60	3.43	2.36

${\text{Mg}}_{\text{o}}^{\text{2+}}$ IC₅₀ values are shown here for the three indicated solution combinations. Because each IC₅₀ value was derived from a single fit to population data, no standard deviation or error is shown.