Electrical stimulation (1–1.5T) of the S1 dorsal root did not increase bladder capacity but 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 duration of PNS and/or S1 DRS. PNS: 5 Hz, 0.2 ms, 1.5T = 0.36 V. S1 DRS: 30 Hz, 0.2 ms, 1.5T = 0.3 V. T: threshold intensity for inducing anal twitch; infusion rate: 2 ml/min. B: summarized bladder capacities measured during different CMGs (n = 7 cats). *Significant difference (P < 0.01, one-way ANOVA). PNS: 3 or 5 Hz, 0.2 ms, 1.5–2T, T = 0.2–0.6 V. S1 DRS: 15 or 30 Hz, 0.2 ms, 1–1.5T, T = 0.16–0.6 V.