Time course of the mean firing rate of WDR neurons. The mean firing rate of a WDR neuron was evoked by application of brushing (A), pressure (B) and pinching (C) stimuli of the skin of the ipsilateral hind paw before, and 2, 5 and 20 min after release of 2-min sciatic nerve pressure. The time that the vascular clip was attached to the sciatic nerve is indicated by the black arrow. Each point (bin) was an average of 11 nerves in the sham group, and 27 nerves in the sciatic pressure group. *p < 0.05, ***p < 0.001, compared with the mean rate of the response before the pressure (sciatic pressure group).