Figure 3

SP-driven inhibitory activity under conditions when glutamatergic driving force is intact. All experiments were performed in bath solution without glutamate receptor antagonists. a, A continuous recording of IPSCs from a lamina V neuron of a NK1R^+/+ mouse. Four traces (bottom) show, at an expanded scale, the IPSCs before, during, 1 sec after, and 9 min after trains of stimulation. The trace during stimulation is at a more expanded scale to show pulse-by-pulse eIPSCs. b, Same as a except the experiment was performed on a NK1R^-/- mouse. The pulse-by-pulse eIPSCs (second trace of lower panel) were similar to those of NK1R^+/+ mice, but ISPCs returned to the basal level immediately after termination of the train stimulation (third trace of lower panel). c, Time course of IPSC frequency (top) and amplitude (bottom). IPSCs during stimulation are not included. d, Peak IPSC frequency and amplitude after trains of stimulation in NK1R^+/+ (n = 6) and NK1R^-/- mice (n = 8). In a–d, stimulation was applied at intensity of 500 μA and a frequency of 20 Hz. e, Capsaicin-induced changes of IPSCs in lamina V neurons of NK1R^+/+ mice (n = 6) and NK1R^-/- mice (n = 16).