Fig. 2: Zn²⁺ inhibits the NH₄Cl-evoked responses in chorda tympani nerve recording and isolated TRCs.

a Chorda tympani response measured from wild-type mice in response to extracellular 100 mM NH₄Cl with and without 10 mM Zn²⁺. b Left panel, normalized CT response measured from the experiment as in a. Right panel, average data (mean ± SEM, n = 5 mice), and scatterplot of the fractional inhibition of the CT response as a function of extracellular Zn²⁺ concentration. c Action potentials were measured from isolated TRCs of wild-type mice in response to extracellular 25 mM K⁺, pH 6.5, and 10 mM NH₄⁺, together with 1 mM Zn²⁺ applied at the times indicated. d Number of action potentials measured in the first 2 s after the stimulus change from experiments as in c. Data from individual cells are shown with connected lines (n = 4). e Dose-dependent inhibition of the NH₄⁺ induced action potentials by Zn²⁺ (pink bar, concentration indicated in μM) measured from isolated TRCs of wild-type mice. f Fractional inhibition measured from data (mean ± SEM) as in e fit with the Hill equation with an IC₅₀ of 0.78 μM and Hill coefficient of 3.2 (n = 4 cells).