Estrogen Replacement Regulates Vaginal Innervations in Ovariectomized Adult Virgin Rats: A Histological Study

Tibial nerve stimulation increases vaginal blood perfusion and bone mineral density and yield load in ovariectomized rat menopause model

INTRODUCTION AND HYPOTHESIS

Human menopause transition and post-menopausal syndrome, driven by reduced ovarian activity and estrogen levels, are associated with an increased risk for symptoms including but not limited to sexual dysfunction, metabolic disease, and osteoporosis. Current treatments are limited in efficacy and may have adverse consequences, so investigation for additional treatment options is necessary. Previous studies have demonstrated that percutaneous tibial nerve stimulation (PTNS) and electro-acupuncture near the tibial nerve are minimally invasive treatments that increase vaginal blood perfusion or serum estrogen in the rat model. We hypothesized that PTNS would protect against harmful reproductive and systemic changes associated with menopause.

METHODS

We examined the effects of twice-weekly PTNS (0.2 ms pulse width, 20 Hz, 2× motor threshold) under ketamine-xylazine anesthesia in ovariectomized (OVX) female Sprague-Dawley rats on menopause-associated physiological parameters including serum estradiol, body weight, blood glucose, bone health, and vaginal blood perfusion. Rats were split into three groups (n = 10 per group): (1) intact control (no stimulation), (2) OVX control (no stimulation), and (3) OVX stimulation (treatment group).

RESULTS

PTNS did not affect serum estradiol levels, body weight, or blood glucose. PTNS transiently increased vaginal blood perfusion during stimulation for up to 5 weeks after OVX and increased areal bone mineral density and yield load of the right femur (side of stimulation) compared to the unstimulated OVX control.

CONCLUSIONS

PTNS may ameliorate some symptoms associated with menopause. Additional studies to elucidate the full potential of PTNS on menopause-associated symptoms under different experimental conditions are warranted.

G-spot: Fact or Fiction?: A Systematic Review

Introduction

The G-spot, a putative erogenous area in the anterior vaginal wall, is a widely accepted concept in the mainstream media, but controversial in medical literature.

Aim

Review of the scientific data concerning the existence, location, and size of the G-spot.

Methods

Search on Pubmed, Pubmed Central, Cochrane, clinicaltrials.gov and Google Scholar from inception to November 2020 of studies on G-spot's existence, location and nature. Surveys, clinical, physiological, imaging, histological and anatomic studies were included.

Main Outcome Measure

Existence, location, and nature of the G-spot.

Results

In total, 31 eligible studies were identified: 6 surveys, 5 clinical, 1 neurophysiological, 9 imaging, 8 histological/anatomical, and 2 combined clinical and histological. Most women (62.9%) reported having a G-spot and it was identified in most clinical studies (55.4% of women); in 2 studies it was not identified in any women. Imaging studies had contradictory results in terms of its existence and nature. Some showed a descending of the anterior vaginal wall, that led to the concept of clitourethrovaginal complex. In anatomic studies, one author could systematically identify the G-spot, while another group did not find it. Studies on innervation of the vaginal walls did not systematically identify an area with richer innervation.

Conclusion

The different studies did systematically agree on the existence of the G-spot. Among the studies in which it was considered to exist, there was no agreement on its location, size, or nature. The existence of this structure remains unproved.

Vieira-Baptista P, Lima-Silva J, Preti M, et al. G-spot: Fact or Fiction?: A Systematic Review. Sex Med 2021;9:100435.