Menthol-evoked cold hypersensitivity is absent in Trpa1-/- mice but present in Trpm8-/- mice. A. Intraplantar administration of 25 mg menthol evoked marked cold hypersensitivity in the ipsilateral paw of lightly restrained Trpm8-/- mice. Note that a greater cold hypersensitivity was seen in Trpm8-/- than in wild-type mice. B. Menthol evoked cold hypersensitivity in wild-type but not Trpa1-/- mice. Data show mean ± SEM for 6 mice/group. * p < 0.05, ** p < 0.01, *** p < 0.001 vs relevant predose values. † p < 0.05, †† p < 0.01, ††† p < 0.001 for contralateral-ipsilateral difference in wild-type mice.