PKA is not involved in NMDA-induced TRPV1 phosphorylation. (A) KT5720, a PKA inhibitor, or vehicle control failed to prevent the NMDA-induced elevation of p-Ser of TRPV1 (*, p < 0.05 in one-way ANOVA; n = 6-8 per group in A and B). (B, C) NMDA-induced mechanical hyperalgesia was only partially attenuated at the dose that completely blocked the forskolin induced mechanical hyperalgesia (*, p < 0.05 in group effects with respect to vehicle condition in two-way ANOVA; #, p < 0.05 to the baseline in post-hoc test; n = 6-8 per group).