TNFα (10 ng/ml, 2 min) suppresses inhibitory synaptic transmission in spinal dorsal horn. A, sIPSCs recorded from a spinal lamina II neuron before (a) and after (b) the application of TNFα; c, frequency of sIPSCs as a function of recording time in the representative cell in a and b. Frequency was measured every 10 s. B, TNFα inhibits sIPSCs in a concentration-dependent manner. The significant effect on sIPSC was observed at 10 (n = 22) and 50 (n = 5) but not 1 (n = 7) ng/ml TNFα. *p < 0.05, **p < 0.01 (one-way ANOVA with post hoc Dunn's test). C, In the presence of DNQX (10 μm) plus d-AP-5 (25 μm) in the bath, application of TNFα still decreased the frequency of sIPSCs. D, Grouped data showed the percentage change (mean ± SEM) in frequency, amplitude, rise time, and decay time of sIPSCs after application of TNFα with (n = 12) and without (n = 22) bath application of DNQX and d-AP-5. **p < 0.01 compared with baseline before application of TNFα (Student's paired t test).