Time-Frequency Analysis of Increases in Vaginal Blood Perfusion Elicited by Long-Duration Pudendal Neuromodulation in Anesthetized Rats

Neuromodulation. 2017 Dec;20(8):807-815. doi: 10.1111/ner.12707. Epub 2017 Oct 16.


Objectives: Female sexual dysfunction (FSD) affects a significant portion of the population. Although treatment options for FSD are limited, neuromodulation for bladder dysfunction has improved sexual function in some women. A few studies have investigated peripheral neuromodulation for eliciting changes in vaginal blood flow, as a proxy for modulating genital sexual arousal, however results are generally transient. Our central hypothesis is that repeated or extended-duration pudendal nerve stimulation can elicit maintained vaginal blood flow increases.

Materials and methods: Under ketamine anesthesia, the pudendal nerve of 14 female rats was stimulated at varying frequencies (1-100 Hz) and durations (0.15-60 min). Vaginal blood perfusion was measured with a laser Doppler flowmetry probe. Changes in blood perfusion were determined through raw signal analysis and increases in the energy of neurogenic (0.076-0.200 Hz) and myogenic (0.200-0.740 Hz) frequency bands through wavelet analysis. Additionally, a convolution model was developed for a carry-over stimulation effect.

Results: Each experiment had significant increases in vaginal blood perfusion due to pudendal nerve stimulation. In addition, there were large concurrent increases in neurogenic and myogenic frequency-band energy in 11/14 experiments, with an average maximal response at 31.3 min after stimulation initiation. An effective stimulation model with a 30-min carry-over effect had a stronger correlation to blood perfusion than the stimulation period itself.

Conclusions: Repeated or extended-duration pudendal nerve stimulation can elicit maintained increases in vaginal blood perfusion. This work indicates the potential for pudendal neuromodulation as a method for increasing genital arousal as a potential treatment for FSD.

Keywords: blood flow; internal organ function; peripheral nerve stimulation; pudendal nerve stimulation; sexual function.

MeSH terms

  • Anesthesia / methods*
  • Animals
  • Electric Stimulation / methods
  • Female
  • Laser-Doppler Flowmetry / methods
  • Pudendal Nerve / blood supply*
  • Pudendal Nerve / physiology
  • Rats
  • Rats, Sprague-Dawley
  • Time Factors
  • Vagina / blood supply*
  • Vagina / innervation*
  • Vagina / physiology