Fig. 3.

The inhibition of AA-induced spinal reflex bladder activity by pudendal nerve stimulation (PNS) is frequency dependent. A: under isovolumetric conditions, bladder rhythmic contractions were inhibited by PNS of different frequencies at an intensity of 2 times the threshold (T) for inducing anal twitching. The horizontal bars under the pressure trace indicate the duration of PNS (0.2 ms, T = 0.5 V). B–D: summarized results produced by 2T PNS. T = 1.0 ± 0.2 V (0.3–2.2 V). n = 12 cats. *Significantly different from 100% (P < 0.05 by a one-sample t-test). The bladder activity in B was measured as the area under the bladder pressure curve during PNS and then normalized to the measurement during the same time period before PNS. Similar normalization was also performed for the maximal contraction amplitude (C) and contraction frequency (D).