Sensory-Tactile Functional Mapping and Use-Associated Structural Variation of the Human Female Genital Representation Field.

The precise location of the human female genital representation field in the primary somatosensory cortex (S1) is controversial and its capacity for use-associated structural variation as a function of sexual behavior remains unknown. We used a functional magnetic resonance imaging (fMRI)-compatible sensory-tactile stimulation paradigm to functionally map the location of the female genital representation field in 20 adult women. Neural response to tactile stimulation of the clitoral region (vs right hand) identified individually-diverse focal bilateral activations in dorsolateral areas of S1 (BA1-BA3) in alignment with anatomic location. We next used cortical surface analyses to assess structural thickness across the 10 individually most activated vertices per hemisphere for each woman. We show that frequency of sexual intercourse within 12 months is correlated with structural thickness of the individually-mapped left genital field. Our results provide a precise functional localization of the female genital field and provide support for use-associated structural variation of the human genital cortex.SIGNIFICANCE STATEMENT We provide a precise location of the human female genital field in the somatosensory cortex and, for the first time, provide evidence in support of structural variation of the human genital field in association with frequency of genital contact. Our study represents a significant methodological advance by individually mapping genital fields for structural analyses. On a secondary level, our results suggest that any study investigating changes in the human genital field must map the field individually to achieve sufficient precision. Our results pave the way for future research into the plasticity of the human genital cortex as a function of normal or adverse experience as well as changes in pathologic conditions, i.e., sexual dysfunction, sexual deviation, or sexual risk-taking behavior.

Innervation of internal female genital organs in the pig during prenatal development.

This study investigated the innervation of internal genital organs in 5-, 7- and 10-week-old female pig foetuses using single and double-labelling immunofluorescence methods. The structure and topography of the organs was examined using a scanning electron microscope (SEM). The investigations revealed differences in the innervation between the three developmental periods. Immunostaining for protein gene product 9.5 (PGP; general neural marker) disclosed solitary nerve fibres in the external part of the gonadal ridge and just outside of the mesenchyme surrounding mesonephric ducts in 5-week-old foetuses. Double-labelling immunohistochemistry revealed that nerve fibres associated with the ridge expressed dopamine ß-hydroxylase (DßH; adrenergic marker) or vesicular acetylcholine transporter (VAChT; cholinergic marker). In 7-week-old foetuses, the PGP-positive nerve terminals were absent from the gonad but some of them ran outside and along, and sometimes penetrated into the mesenchyme surrounding the tubal and uterine segments of the paramesonephric ducts and uterovaginal canal. Few axons penetrated into the mesenchyme. DßH-positive fibres were found in single nerve strands or bundles distributed at the edge of the mesenchyme. VAChT-positive nerve terminals formed delicate bundles located at the edge of the mesenchyme, and the single nerves penetrated into the mesenchyme. DßH was also expressed by neurons which formed cell clusters comprising also DßH- or VAChT-positive nerve fibres. In 10-week-old foetuses, PGP-positive nerve fibres were still absent from the ovary but some were distributed in the mesenchyme associated with the uterovaginal canal and uterine and a tubal segment of the paramesonephric ducts, respectively. DßH- or VAChT-positive nerve fibres were distributed at the periphery of the mesenchyme associated with the uterovaginal canal. Some DßH- and many VAChT-positive nerve fibres were evenly distributed throughout the mesenchyme. The clusters of nerve cells comprised DßH-positive perikarya and DßH- or VAChT-positive nerve fibres. The investigations revealed no DßH/VAChT-positive nerve fibres or neurons as well as no nerve structures stained for calcitonin gene-related peptide and/or substance P (sensory markers) associated with the genital organs in the studied prenatal periods.

Repeat periods of electrical stimulation prolong the modulation of the micturition reflex in the rat.

AIMS: The aim of this study was to determine if the duration of the micturition reflex modulation could be prolonged by repeated periods of afferent stimulation in the decorticated rat. METHODS: Eighteen female Sprague-Dawley rats were used for the study, 10 for intravesical electrical stimulation (IVES), and 8 for Ano-genital pudendal afferents stimulation. Repeated constant flow cystometries were performed with body-warm saline (0.06-0.1 mL/min) at about 10 min interval. The selected afferents were stimulated continuously for 5 min at maximal intensity. The same stimulation was repeated six times with a pause of 5 min between the stimulations. The mean threshold volume of cystometries performed during one hour before and each hour after the stimulation were compared. RESULTS: After six periods of IVES, the micturition threshold volume decreased to its lowest value (62% of control) during the first hour and remained at 80% 4 h later (n = 10, P < 0.01). Ano-genital afferent stimulation produced a corresponding increase in the micturition threshold volume. The long-lasting poststimulation effect was again observed for more than 5 h. During the first hour the mean threshold volume increased to 211% of controls and it remained at about this level for the entire observation period (n = 8, P < 0.01). CONCLUSIONS: Repeated short periods of stimulation prolonged the modulatory effect well beyond the stimulation period. The findings provide experimental evidence supporting the clinical application of IVES and ano-genital stimulation for treatment of neurogenic urinary bladder dysfunction.

Quality of Life After Radical Cystectomy.

Approximately 1 in 5 new cases of clinically localized bladder cancer is muscle invasive and requires the patient to choose from 1 of 2 prevailing options for treatment: radical cystectomy or radiation to the bladder. However, these treatments are associated with detrimental effects on patient well-being and quality of life, particularly with respect to functional independence, urinary and sexual function, social and emotional health, body image, and psychosocial stress. Compared with the literature on other malignancies like breast or prostate cancer, high-quality studies evaluating the effects of bladder cancer treatment on quality of life are lacking.

The Effects of a Genital Vibratory Stimulation Device on Sexual Function and Genital Sensation.

OBJECTIVE: The aim of this study was to evaluate the effectiveness of a genital vibratory stimulation device in improving sexual function in women with arousal and orgasm disorders. METHODS: In this single-arm, prospective study, baseline and 1- and 3-month assessments were performed to evaluate women with sexual arousal and/or orgasmic disorders, who received therapy using a genital vibratory stimulation device. Sexual function, satisfaction, and distress were evaluated using the Female Sexual Function Index (FSFI), the Female Sexual Distress Scale, and the Female Intervention Efficacy Index questionnaires. Genital sensation was evaluated using quantitative sensory testing. RESULTS: Seventy women, aged 19 to 64 years, were evaluated from October 2009 to August 2013. Forty-seven (67.1%) and 37 (52.9%) women completed 1- and 3-month follow-ups, respectively. The FSFI arousal and orgasm domain scores and total FSFI scores improved at 1 and 3 months (P < 0.001 for all outcomes). Mean (SD) total FSFI scores increased from 20.04 (4.65) (baseline) to 25.03 (5.21) (1 month) to 26.66 (5.42) (3 months; both Ps < 0.0001). Female Sexual Distress Scale scores reflected significantly decreased distress at 1 (P = 0.0006) and 3 (P < 0.0001) months compared with baseline and at 3 months compared with 1 month (P = 0.03). Neurological sensation was increased at all genital sites at 1 and 3 months (P < 0.0001 for all). After adjustment for age, there was a significant interaction between arousal domain scores and clitoral and right labial sensation. At 3 months, perceptions of increased vaginal lubrication, orgasm, and genital sensation were reported by 67.5%, 65.0%, and 82.5% of the participants. No major adverse events were noted. CONCLUSIONS: Genital vibratory stimulation device use resulted in uniform improvements in sexual function, satisfaction, sexually related distress and genital sensation.

Urogenital and Sexual Complaints in Female Club Cyclists-A Cross-Sectional Study.

INTRODUCTION: Cycling has gained increased popularity among women, but in contrast to men, literature on urogenital overuse injuries and sexual dysfunctions is scarce. AIM: To determine the prevalence and duration of urogenital overuse injuries and sexual dysfunctions in female cyclists of the largest female cycling association in The Netherlands. METHODS: A cross-sectional questionnaire survey was sent to 350 members of the largest female Dutch cycling association and 350 female members of a Dutch athletics association (runners). MAIN OUTCOME MEASURES: The prevalence and duration of urogenital overuse injuries and sexual complaints were assessed using predefined international definitions. RESULTS: Questionnaire results of 114 cyclists (32.6%) and 33 runners (9.4%) were analyzed. After at least 2 hours of cycling, dysuria, stranguria, genital numbness, and vulvar discomfort were present in 8.8%, 22.2%, 34.9%, and 40.0%, respectively (maximum duration 48 hours). These complaints are not present in the controls (P < .001). In multivariable logistic regression analysis, increased saddle width was significantly associated with the presence of dysuria and stranguria. Older age was significantly associated to the presence of vulvar discomfort. Of the cyclists, 50.9% has at least one urogenital overuse injury. Insertional dyspareunia was present in 40.0% of cyclists and lasted until 48 hours after the effort. The latter complaint was not present in runners (P < .001). Uni- or bilateral vulvar edema was reported by 35.1% of cyclists. As for general complaints, 18.4% of cyclists reported a change in sexual sensations and 12.8% reported difficulties in reaching orgasm owing to cycling-related complaints. Limitations include population size and the use of non-validated questionnaires. CONCLUSIONS: The results of this study suggest that urogenital overuse injuries and sexual complaints are highly prevalent in female cyclists who are active participants in riding groups.

[A Matter of Nerves - Applied Neurophysiology of Female Sexuality]. / Nervensache - praxisorientierte Neurophysiologie der weiblichen Sexualität.

Sexual problems are often attributed to psychological or physical deficits that are difficult to modify, or to a poor lover. In contrast, the neurophysiological interaction between body and brain can be understood as fundamental for the genital and emotional experience of sexuality. Neuropsychological discoveries and clinical observations show that elevated muscle tension, superficial breathing and reduced body movement, as employed by many individuals during sexual arousal, will limit the perception of arousal and the degree of sexual pleasure. In contrast, deep breathing and variations in movement and muscle tension support it. Through the use of self awareness exercises and physical learning steps, patients can integrate their sexuality and increases its resistance to psychological, medical and relational interferences.

Terminal innervation of female genitalia, cutaneous sensory receptors of the epithelium of the labia minora.

INTRODUCTION: Little information is available regarding the sensory nerve endings within the glabrous skin of the external female genitalia. The diversity of possible sensations suggests a variety of receptor types. Comprehensive knowledge of the sensory stimuli, including stimulus position, changes in temperature, pressure and pain, is critical for addressing pain and sexual function disorders clinically. The aim of this neuro-histological study is document the presence and characteristics of cutaneous sensory receptors in female genital tissue. MATERIALS AND METHODS: Labial skin samples were obtained from ten normal girls (aged 1-9 years). The specimens were waste tissue obtained during surgical intervention. They were all obtained by the senior investigator, a pediatric urologist, after the parent or legal guardian had given informed consent. The specimens were stained by Cajal-type silver impregnation and by immunocytochemistry against protein gene product (PGP) 9.5 and neuron-specific enolase (NSE). RESULTS: PGP 9.5 was the most sensitive neural marker for identifying cutaneous sensory receptors. Free nerve endings (FNEs) in the papillary dermis appeared as thin fibers, varicose, branched or single processed, straight or bent. In the labia minora, FNEs were identified in the strata basale, spinosum and granulosum of the epidermis. Non-capsulated (Meissner-like) corpuscles in the dermal papillae interdigitated with epidermal ridges of the skin. Capsulated corpuscles protruded from the deep dermis into the epidermis. Encapsulated corpuscles and cells located in the inner and outer cores were strongly positive for PGP 9.5. CONCLUSIONS: FNEs, Meissner's corpuscles and Pacinian corpuscles are present in the female labia minora and exhibit characteristic staining patterns.

Estrogen and female reproductive tract innervation: cellular and molecular mechanisms of autonomic neuroplasticity.

The female reproductive tract undergoes remarkable functional and structural changes associated with cycling, conception and pregnancy, and it is likely advantageous to both individual and species to alter relationships between reproductive tissues and innervation. For several decades, it has been appreciated that the mammalian uterus undergoes massive sympathetic axon depletion in late pregnancy, possibly representing an adaptation to promote smooth muscle quiescence and sustained blood flow. Innervation to other structures such as cervix and vagina also undergo pregnancy-related changes in innervation that may facilitate parturition. These tissues provide highly tractable models for examining cellular and molecular mechanisms underlying peripheral nervous system plasticity. Studies show that estrogen elicits rapid degeneration of sympathetic terminal axons in myometrium, which regenerate under low-estrogen conditions. Degeneration is mediated by the target tissue: under estrogen's influence, the myometrium produces proteins repulsive to sympathetic axons including BDNF, neurotrimin, semaphorins, and pro-NGF, and extracellular matrix components are remodeled. Interestingly, nerve depletion does not involve diminished levels of classical sympathetic neurotrophins that promote axon growth. Estrogen also affects sympathetic neuron neurotrophin receptor expression in ways that appear to favor pro-degenerative effects of the target tissue. In contrast to the uterus, estrogen depletes vaginal autonomic and nociceptive axons, with the latter driven in part by estrogen-induced suppression of BMP4 synthesis. These findings illustrate that hormonally mediated physiological plasticity is a highly complex phenomenon involving multiple, predominantly repulsive target-derived factors acting in concert to achieve rapid and selective reductions in innervation.

Persistent genital hyperinnervation following progesterone administration to adolescent female rats.

Provoked vestibulodynia, a female pelvic pain syndrome affecting substantial numbers of women, is characterized by genital hypersensitivity and sensory hyperinnervation. Previous studies have shown that the risk of developing provoked vestibulodynia is markedly elevated following adolescent use of oral contraceptives with high progesterone content. We hypothesized that progesterone, a steroid hormone with known neurotropic properties, may alter genital innervation through direct or indirect actions. Female Sprague Dawley rats received progesterone (20 mg/kg subcutaneously) from Days 20-27; tissue was removed for analysis in some rats on Day 28, while others were ovariectomized on Day 43 and infused for 7 days with vehicle or 17beta estradiol. Progesterone resulted in overall increases in vaginal innervation at both Day 28 and 50 due to proliferation of peptidergic sensory and sympathetic (but not parasympathetic) axons. Estradiol reduced innervation in progesterone-treated and untreated groups. To assess the mechanisms of sensory hyperinnervation, we cultured dissociated dorsal root ganglion neurons and found that progesterone increases neurite outgrowth by small unmyelinated (but not myelinated) sensory neurons, it was receptor mediated, and it was nonadditive with NGF. Pretreatment of ganglion with progesterone also increased neurite outgrowth in response to vaginal target explants. However, pretreatment of vaginal target with progesterone did not improve outgrowth. We conclude that adolescent progesterone exposure may contribute to provoked vestibulodynia by eliciting persistent genital hyperinnervation via a direct effect on unmyelinated sensory nociceptor neurons and that estradiol, a well-documented therapeutic, may alleviate symptoms in part by reducing progesterone-induced sensory hyperinnervation.

Pudendal nerve 3-dimensional illustration gives insight into surgical approaches.

The pudendal nerve is located topographically in areas in which plastic surgeon reconstruct the penis, the vagina, the perineum, and the rectum. This nerve is at risk for either compression or direct injury with neuroma formation from obstetrical, urogynecologic, and rectal surgery as well as pelvic fracture and blunt trauma. The purpose of this study was to create a 3-dimensional representation based on magnetic resonance imaging of the pelvis supplemented with new anatomic dissections in men and women to delineate the location of the pudendal nerve and its branches, providing educational information both for surgical intervention and patient education. The results of this study demonstrated that most often there are at least 2, not 1, "pudendal nerves trunks" as they leave the pelvis to transverse the sacrotuberous ligament, and that there are most often 2, not 1, exit(s) from Alcock canal, one for the dorsal branch and one for the perineal branch of the pudendal nerve.

Mating regulates neuromodulator ensembles at nerve termini innervating the Drosophila reproductive tract.

Upon mating, regions of the female reproductive tract mature and alter their function [1-3], for example to facilitate storage of sperm or control the release of eggs [4-6]. The female's nervous system and neuromodulators play important roles in her responses to mating [7-13]. However, it is difficult to reconcile the reproductive tract's many changing but coordinated events with the small set of neuromodulators present [14-18]. We hypothesized that each part of the reproductive tract contains a characteristic combination of neuromodulators that confer unique identities on each region and that postmating changes in these combinations coordinate subsequent actions. We examined the presence, locations, and levels of neuromodulators and related molecules ("signaling molecules") in the reproductive tract of Drosophila melanogaster females before and after mating: the biogenic amine octopamine, which regulates ovulation rate in Drosophila and locusts [7, 14-20]; serotonin, which regulates muscle contraction in locust oviducts [21]; and the FMRF amide dromyosuppressin, which regulates contraction of Drosophila heart muscle [22] and may regulate muscle contractions in the reproductive tract, if it is expressed there. We find that separate aspects of mating (sperm, seminal proteins, and physical effects) independently modulate the release of signaling molecules. Each reproductive tract subregion displays a characteristic combination of signaling molecule release, resulting in a unique functional identity. These patterns, and thus functions, change reproducibly after mating. Thus, one event (mating) promotes new combinations of signaling molecules that endow different parts of the reproductive tract with unique temporal and spatial identities that facilitate many aspects of fertilization.

Chronic stress and sexual function in women.

INTRODUCTION: Chronic stress is known to have negative effects on reproduction, but little is known about how it affects the sexual response cycle. The present study examined the relationship between chronic stress and sexual arousal and the mechanisms that mediate this relationship. AIM: The aim of this study is to test the relationship between chronic stress and sexual arousal and identify mechanisms that may explain this relationship. We predicted that women experiencing high levels of chronic stress would show lower levels of genital arousal and dehydroepiandrosterone (DHEAS) and higher levels of cortisol and cognitive distraction compared with women with average levels of stress. METHODS: Women who were categorized as high in chronic stress (high stress group; n=15) or average in chronic stress (average stress group; n=15) provided saliva samples and watched an erotic film while having their genital and psychological arousal measured. MAIN OUTCOME MEASURES: Main outcome measures were vaginal pulse amplitude, psychological arousal, salivary cortisol, salivary DHEAS, and heart rate and compared them between women with high and average levels of chronic stress. RESULTS: Women in the high stress group had lower levels of genital, but not psychological arousal, had higher levels of cortisol, and reported more distraction during the erotic film than women in the average stress group. The main predictor of decreased genital sexual arousal was participants' distraction scores. CONCLUSIONS: High levels of chronic stress were related to lower levels of genital sexual arousal. Both psychological (distraction) and hormonal (increased cortisol) factors were related to the lower levels of sexual arousal seen in women high in chronic stress, but distraction was the only significant predictor when controlling for other variables.

Psychophysical properties of female genital sensation.

Provoked vestibulodynia (PVD) is characterized by the presence of vulvar touch and pain hypersensitivity. Pain with vaginal distension, which motivates treatment seeking and perpetuates distress, is frequently reported with PVD. However, the concordance between the perception of vulvar and vaginal sensation (ie, somatic and visceral genital sensations, respectively) remains unstudied in healthy women, as well as in clinical populations such as PVD. To evaluate the static and dynamic (time-varying) properties of somatic and visceral genital sensation, women with PVD (n=14) and age- and contraceptive-matched healthy controls (n=10) rated varying degrees of nonpainful and painful genital stimulation. Somatic (vulvar) mechanical sensitivity to nonpainul and painful degrees of force were compared to visceral (vaginal) sensitivity to nonpainful and painful distension volumes. Results indicated that healthy women showed substantial individual variation in and high discrimination of vulvar and vaginal sensation. In contrast, PVD was associated with vulvar allodynia and hyperalgesia, as well as vaginal allodynia. Modeling of dynamic perception revealed novel properties of abnormal PVD genital sensation, including temporal delays in vulvar touch perception and reduced perceptual thresholds for vaginal distension. The temporal properties and magnitude of PVD distension pain were indistinguishable from vaginal fullness in healthy controls. These results constitute the first empirical comparison of somatic and visceral genital sensation in healthy women. Findings provide novel insights into the sensory abnormalities that characterize PVD, including an experimental demonstration of visceral allodynia. This investigation challenges the prevailing diagnostic assessment of PVD and reconceptualizes PVD as a chronic somatic and visceral pain condition.

Elevated androgens during puberty in female rhesus monkeys lead to increased neuronal drive to the reproductive axis: a possible component of polycystic ovary syndrome.

BACKGROUND: Hyperandrogenemia is associated with several clinical disorders in which both reproductive dysfunction and metabolic changes may coexist [i.e. polycystic ovary syndrome (PCOS), obesity and congenital adrenal hyperplasia]. Moreover, there is growing evidence that the elevated levels of circulating androgens in obese girls may lead to an increased neuroendocrine drive to the reproductive axis, similar to that associated with PCOS. METHODS: To test whether androgen exposure in the childhood and adolescent period could lead to pubertal alterations in LH secretory patterns, female rhesus monkeys received subcutaneous testosterone implants prepubertally beginning at 1 year of age, maintaining a 3.7-fold increase (P = 0.001) in circulating testosterone levels over cholesterol-implant controls (n = 6/group) into the post-pubertal period. In early adulthood, pulsatile secretion of LH was measured over 12 h during the early follicular phase of a menstrual cycle, and responsiveness of the pituitary to gonadotrophin-releasing hormone was determined. In addition, ultrasounds were performed to assess ovarian morphology and glucose tolerance testing was performed to assess insulin sensitivity. RESULTS: The timing of menarche was similar between groups. Testosterone-treated animals had a significantly greater LH pulse frequency during the early follicular phase compared with controls (P = 0.039) when measured at 5 years of age. There was a larger LH response to GnRH when testosterone-treated animals were 4 years of age (P = 0.042), but not when the animals were 5 years old (P = 0.57). No differences were seen in insulin sensitivity or ovarian morphology, and the groups showed similar rates of ovulation in early adulthood. CONCLUSIONS: Exposure to increased levels of androgens over the course of pubertal development appears to trigger physiological changes in the neural drive to the reproductive axis that resemble those of obese hyperandrogenemic girls in early adulthood and are characteristic of PCOS.

Women's bike seats: a pressing matter for competitive female cyclists.

INTRODUCTION: There are numerous genital complaints in women cyclists, including pain, numbness, and edema of pelvic floor structures. Debate ensues about the best saddle design for protection of the pelvic floor. AIM: To investigate the relationships between saddle design, seat pressures, and genital nerve function in female, competitive cyclists. METHODS: We previously compared genital sensation in healthy, premenopausal, competitive women bicyclists and runners. The 48 cyclists from our original study comprise the study group in this subanalysis. MAIN OUTCOME MEASURES: Main outcome measures were: (i) genital vibratory thresholds (VTs) determined using the Medoc Vibratory Sensation Analyzer 3000 and (ii) saddle pressures as determined using a specially designed map sensor. RESULTS: More than half of the participants (54.8%) used traditional saddles, and the remainder (45.2%) rode with cut-out saddles. On bivariate analysis, use of traditional saddles was associated with lower mean perineal saddle pressures (MPSP) than riding on cut-out saddles. Peak perineal saddle pressures (PPSP) were also lower; however, the difference did not reach statistical significance. Saddle design did not affect mean or peak total saddle pressures (MTSP, PTSP). Saddle width was significantly associated with PPSP, MTSP, and PTSP but not with MPSP. Women riding cut-out saddles had, on average, a 4 and 11 kPa increase in MPSP and PPSP, respectively, compared with women using traditional saddles (P = 0.008 and P = 0.010), after adjustment for other variables. Use of wider saddles was associated with lower PPSP and MTSP after adjustment. Although an inverse correlation was seen between saddle pressures and VTs on bivariate analysis, these differences were not significant after adjusting for age. CONCLUSION: Cut-out and narrower saddles negatively affect saddle pressures in female cyclists. Effects of saddle design on pudendal nerve sensory function were not apparent in this cross-sectional analysis. Longitudinal studies evaluating the long-term effects of saddle pressure on the integrity of the pudendal nerve, pelvic floor, and sexual function are warranted.

Hysterectomy improves sexual response? Addressing a crucial omission in the literature.

The prevailing view in the literature is that hysterectomy improves the quality of life. This is based on claims that hysterectomy alleviates pain (dyspareunia and abnormal bleeding) and improves sexual response. Because hysterectomy requires cutting the sensory nerves that supply the cervix and uterus, it is surprising that the reports of deleterious effects on sexual response are so limited. However, almost all articles that we encountered report that some of the women in the studies claim that hysterectomy is detrimental to their sexual response. It is likely that the degree to which a woman's sexual response and pleasure are affected by hysterectomy depends not only on which nerves were severed by the surgery, but also the genital regions whose stimulation the woman enjoys for eliciting sexual response. Because clitoral sensation (via pudendal and genitofemoral nerves) should not be affected by hysterectomy, this surgery would not diminish sexual response in women who prefer clitoral stimulation. However, women whose preferred source of stimulation is vaginal or cervical would be more likely to experience a decrement in sensation and consequently sexual response after hysterectomy because the nerves that innervate those organs, that is, the pelvic, hypogastric, and vagus nerves, are more likely to be damaged or severed in the course of hysterectomy. However, all published reports of the effects of hysterectomy on sexual response that we encountered fail to specify the women's preferred sources of genital stimulation. As discussed in the present review, we believe that the critical lack of information as to women's preferred sources of genital stimulation is key to accounting for the discrepancies in the literature as to whether hysterectomy improves or attenuates sexual pleasure.

Sensory innervation of the external genital tract of female guinea pigs and mice.

INTRODUCTION: The structural and neurochemical characterization of the sensory innervation of the external genitalia of females is poorly known. AIMS: To immunohistochemically map the sensory innervation of external genitalia and surrounding structures of female guinea pigs and mice. METHODS: Large-diameter sensory fibers, presumably mechanoreceptors, were identified by their immunoreactivity to neuron-specific enolase (NSE) or vesicular glutamate transporter 1 (VGluT1). Peptidergic sensory fibers, presumably unmyelinated nociceptors, were identified by their immunoreactivity to calcitonin gene-related peptide (CGRP), substance P, or both. Multiple-labelled tissues were examined with high-resolution confocal microscopy. MAIN OUTCOME MEASURES: Microscopic identification of sensory endings, including potential nociceptors, characteristic of the external genitalia. RESULTS: Large complex nerve endings immunoreactive for NSE and VGluT1 were abundant in dermal papillae of the clitoris. Each large ending was accompanied by one or two fine fibers immunoreactive for CGRP but neither substance P nor VGluT1. More simple NSE-immunoreactive endings occurred within dermal papillae in non-hairy skin of the labia and anal canal but were rare in pudendal or perineal hairy skin. Fine intra-epithelial fibers immunoreactive for NSE but not CGRP were abundant in hairy skin but rare in non-hairy genital skin and the clitoris. Only fine varicose fibers immunoreactive for both CGRP and substance P occurred in connective tissue underlying the mucosal epithelium of cervix and endometrium. CONCLUSION: Compared with surrounding tissues, the sensory innervation of the clitoris is highly specialized. The coactivation of nociceptors containing CGRP but not substance P within each mechanoreceptor complex could be the explanation of pain disorders of the external genitalia.

Is there an association between female urinary incontinence and decreased genital sensation?

AIM: To explore the relationship between urinary incontinence and genital sensory functioning in females with sexual dysfunction disorders. METHODS: A retrospective consecutive chart review was conducted for all women who were referred to our tertiary female urology clinic with a primary complaint of sexual dysfunction between October 1999 and January 2009. Our study sample included 177 women, all of whom underwent a thorough clinical evaluation. Urinary incontinence was diagnosed based on clinical history and physical examination by a urogynecologist. The Genital Thermal and Vibratory Sensory Analyzer (GSA) was used for sensory testing in the genital area. Independent t-test and multivariate linear regression were used for statistical analysis. RESULTS: Of the 177 study patients (median age 34, range 18-68), 63 (36%) had urinary incontinence. Women with urinary incontinence were found to be less sensitive to warm, cold, and vibratory thresholds at both the anterior and the posterior vaginal wall and the clitoral area (P < 0.05). CONCLUSIONS: Women with urinary incontinence and sexual dysfunction are less sensitive to all sensory testing in the genital region than women with sexual dysfunction alone. This relationship may be attributable to afferent nerve damage and the critical role it may play in the etiology of urinary incontinence.

The role of genital nerve afferents in the physiology of the sexual response and pelvic floor function.

INTRODUCTION: Our understanding of genital and pelvic floor physiology is rapidly expanding. Penile erection is a neurovascular event controlled by spinal autonomic centers, the activity of which is dependent on input from supraspinal centers and the genitalia. Genital afferent stimulation excites spinal autonomic nuclei and supraspinal sexual centers of both genders. AIM: To present a detailed understanding of the functional importance of genital afferent neuroanatomy and neurophysiology. METHODS: English-written articles of diverse disciplines from 1980 to 2010 that contained information on genital anatomy, pudendal/dorsal/perineal/cavernous nerves, vibratory stimulation, reflexogenic erection, peripheral/central nervous system-mediated erectile and micturition pathways, and sexual arousal in animals and humans were reviewed. MAIN OUTCOME MEASURES: Analysis of supporting evidence for the role of genital afferents in the physiology of erectile response and pelvic floor function. RESULTS: Basic science and clinical studies support the concept that pudendal nerve circuitry serves an essential purpose for sexual behavior, erectile function, penile rigidity, ejaculation, and micturition. Males and females share a comparable pattern of genital afferent neuroanatomy and neurophysiology, and sexual and micturition reflexes are similar in both genders. Pudendal nerve branches communicate with the cavernous nerves and are nitric oxide synthase positive. Genital afferents activate multiple spinal reflexes that modulate erection and micturition. Genital sensory information is transmitted to supraspinal centers important for sexual function. CONCLUSIONS: There is expanding support for the critical role of genital afferent neurophysiology in the mechanisms of erectile function and micturition. Genital afferent stimulation is a safe and natural modality that can be harnessed to amplify autonomic and somatic activity within the penis, female genitalia, spinal cord, and higher centers via established neurological principles. Such physiological adaptive processes may be beneficial in improving sexual response, erectile function, and micturition in many disease states, including in men after radical pelvic surgery. Well-designed and -executed studies in each specific population are needed to authenticate such prospects.