Loss of TRESK increases the excitability of small IB4− TG neurons expressing TRPM8 but not those expressing VGLUT3. A, Representative traces of APs generated by incremental depolarizing current injections in TG neurons from WT_TRPM8EGFP and KO_TRPM8EGFP mice. The values of Vrest and the current amplitude are indicated. B, Mean rheobase of EGFP+ TG neurons from WT_TRPM8EGFP and KO_TRPM8EGFP mice (n = 14 and 18 neurons, respectively). **p < 0.01; two-tailed t test. C, The spike frequency in response to incremental depolarizing current injections in EGFP+ TG neurons from WT_TRPM8EGFP and KO_TRPM8EGFP mice (same neurons as in C). #p < 0.05; two-way RM ANOVA. *p < 0.05, **p < 0.01; two-tailed t test between the corresponding WT and KO groups. D, E, Mean rheobase and spike frequency of EGFP+ TG neurons from WT_VGLUT3EGFP and KO_VGLUT3EGFP mice (n = 19 and 27 neurons, respectively).