Fig. 3.

The preconditioned and diffuse noxious inhibitory controls (DNIC) response profiles of ipsilateral wide dynamic range neurons before and after spinal application of SB-269970 (100 μg/50 μl) or AS-19 (100 μg/50 μl) in early- and late-phase monoiodoacetate (MIA) animals, respectively. A: in early-phase MIA animals, spinal application of the 5-HT₇ receptor antagonist SB-269970 reduced the magnitude of neuronal inhibition induced by a conditioning noxious ear pinch, but both before and after application there remained a significant reduction in mechanically evoked neuronal firing with concurrent ear pinch (n = 6). B: in late-phase MIA animals, the spinal application of the 5-HT₇ receptor agonist AS-19 restored DNIC-induced neuronal inhibition such that a noxious conditioning ear pinch produced a significant reduction in mechanically evoked neuronal firing (n = 6). *P < 0.05; **P < 0.01; ***P < 0.001; two-way ANOVA with Bonferroni correction.