Calcium responses to glutamate in Type II and Type III taste cells. A: In T1R3-GFP cells, only high concentrations of glutamate (100 mM) elicit a calcium response. B: In GAD67-GFP cells, glutamate at 10 mM or 1 mM may elicit a calcium response. Type III cells possess voltage-gated calcium channels and respond to high concentrations of KCl (55 mM). C: In GAD67-GFP cells, NBQX, a specific antagonist of AMPA/Kainate receptors partially inhibited the response to 1 mM glutamate. D: Average effect of NBQX on responses to glutamate (One way repeated measures ANOVA with a Tukey post test; **: P < 0.005; *: P < 0.05, n = 9 cells).