(A) Sample traces show SA1 impulses elicited by a 38-µm whisker hair deflection in normal bath solution (control, upper panel) and in the presence of 1 mM ATP (lower panel). (B) Summary data of the SA1 frequency at different time points during whisker hair deflection before (control, circles) and following the bath application of 1 mM ATP (squares). (C-F) Similar to B except 100 µM α,β-methylene-ATP (C), 1 mM glutamate (D), 1 mM GABA (E), or 1 mM histamine (F) was tested (n = 6 in each test). Data represent the mean ± SEM. No significant difference was found in each test, two-way ANOVA with Bonferroni post-hoc tests.