Cold hypersensitivities evoked by icilin and LPC are absent in Trpm8-/- mice but retained in Trpa1-/- mice. Effects of intraplantar administration of either 60 μg LPC (A) or 100 μg icilin (B) on cold withdrawal latencies in lightly restrained Trpm8-/- and wild-type littermate mice. Neither compound had an effect on withdrawal latency for the injected (ipsilateral) paw in Trpm 8-/- mice. Both compounds reduced the ipsilateral paw withdrawal latencies in wild-type littermates, but had no effect on withdrawal latencies for the uninjected (contralateral) paw. Intraplantar LPC (C) or icilin (D) reduced paw withdrawal thresholds for ipsilateral paws in both Trpa1-/- and wild-type littermate mice. Note that a greater cold hypersensitivity was seen in Trpa1-/- than in wild-type 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 for contralateral-ipsilateral difference in wild-type mice.