A depolarizing stimulus of high K+ solution does not increase [Ca2+]i in bitter, sweet, and umami sensitive cells. Panel A shows an isolated non-GFP cell from a T1R3-GFP expressing animal. Some non-GFP cells do present an increase in [Ca2+]i when challenged with high K+ solution. Cells that have [Ca2+]i responses to high K+ do not respond to the PLC agonist m-3M3FBS, 10 μM. T1R3-GFP expressing cells in Panel B do not show changes in [Ca2+]i to bath applied high K+ but do show reversible increases in [Ca2+]i to bath applied PLC agonist m-3M3FBS (10 μM). TRPM5-GFP expressing cells in Panel C do not change [Ca2+]i to high K+ but show reversible increases in [Ca2+]i when 10 μM m-3M3FBS is present.