Fig. 4.

TRPA1-dependent cold responses in TG neurons. (A) Ratiometric measurement of changes in intracellular Ca²⁺ in response to cold, menthol (100 μM), MO (100 μM), or capsaicin (1 μM), illustrating the 3 types of cold-sensitive TG neurons. (B) Comparison of the percentage of cells responding to cold and chemical stimuli in preparations from WT and Trpa1^−/− mice. (C) Pie charts showing the percentage of cold-insensitive and the 3 types of cold-sensitive neurons in TG from WT and Trpa1^−/− mice. (D) Histogram comparing temperature thresholds in cold-sensitive TG from WT and Trpa1^−/− mice. The temperature threshold was defined as the temperature at which the ratio was increased by 10% of the maximal cold-induced increase. (E) Correlation of the amplitude of the MO and cold responses in MO-sensitive neurons from WT mice (n = 177). The solid line represents a linear fit to the data.