Electrical stimulation (1.5–2T) of the S1 dorsal root increased bladder capacity, but also removed the increase in bladder capacity induced by pudendal nerve stimulation (PNS). A: repeated cystometrogram (CMG) traces with/without PNS and/or S1 dorsal root stimulation (DRS). The black bars under the CMG traces indicate the durations of PNS and/or S1 DRS. PNS: 5 Hz, 0.2 ms, 1.5T = 0.9 V. S1 DRS: 15 Hz, 0.2 ms, 2T = 0.4 V. T: threshold intensity for inducing anal twitch; infusion rate: 3 ml/min. B: summarized bladder capacities measured during different CMGs (n = 6 cats). *Significant difference (P < 0.05, one-way ANOVA). PNS: 3–5 Hz, 0.2 ms, 1.5–2T, T = 0.2–0.6 V. S1 DRS: 15 or 30 Hz, 0.2 ms, 1.5–2T, T = 0.16–0.36 V.