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Egg laying in the nematode worm Caenorhabditis elegans is a two-state behavior modulated by internal and external sensory input. We have previously shown that homeostatic feedback of embryo accumulation in the uterus regulates bursting activity of the serotonergic HSN command neurons that sustains the egg-laying active state. How sensory feedback of egg release signals to terminate the egg-laying active state is less understood. We find that Gαo, a conserved Pertussis Toxin-sensitive G protein, signals within HSN to inhibit egg-laying circuit activity and prevent entry into the active state. Gαo signaling hyperpolarizes HSN, reducing HSN Ca2+ activity and input onto the postsynaptic vulval muscles. Loss of inhibitory Gαo signaling uncouples presynaptic HSN activity from a postsynaptic, stretch-dependent homeostat, causing precocious entry into the egg-laying active state when only a few eggs are present in the uterus. Feedback of vulval opening and egg release activates the uv1 neuroendocrine cells which release NLP-7 neuropeptides which signal to inhibit egg laying through Gαo-independent mechanisms in the HSNs and Gαo-dependent mechanisms in cells other than the HSNs. Thus, neuropeptide and inhibitory Gαo signaling maintain a bi-stable state of electrical excitability that dynamically controls circuit activity in response to both external and internal sensory input to drive a two-state behavior output., (© The Author(s) 2021. Published by Oxford University Press on behalf of Genetics Society of America. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Objective: The aim of this study was to introduce a new method of labiaplasty. Here, we describe the surgical procedure, outcomes and the advantages of this method., Method: The medical records of 21 patients aged between 20 and 45 years who underwent reduction of the labia minora from February 2015 to June 2017 were reviewed. The procedures performed in these studies used posterior-lateral wedge resection with preservation of the central blood vessels and nerve bundle., Results: All the surgeries were performed successfully, and 21 patients experienced an uneventful postoperative period. A minor dehiscence occurred in one patient, who recovered with no requirement for additional treatment. All of the patients were satisfied with the eventual esthetic appearance., Conclusion: The posterior-lateral wedge resection with preservation of the central blood vessels and nerve bundle is a simple and safe method that is associated with satisfactory outcomes., Level of Evidence Iv: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Background  This study describes outcomes from a new surgical approach to treat "anterior" pudendal nerve symptoms in women by resecting the perineal branches of the pudendal nerve (PBPN). Methods  Sixteen consecutive female patients with pain in the labia, vestibule, and perineum, who had positive diagnostic pudendal nerve blocks from 2012 through 2015, are included. The PBPN were resected and implanted into the obturator internus muscle through a paralabial incision. The mean age at surgery was 49.5 years (standard deviation [SD] = 11.6 years) and the mean body mass index was 25.7 (SD = 5.8). Out of the 16 patients, mechanisms of injury were episiotomy in 5 (31%), athletic injury in 4 (25%), vulvar vestibulectomy in 5 (31%), and falls in 2 (13%). Of these 16 patients, 4 (25%) experienced urethral symptoms. Outcome measures included Female Sexual Function Index (FSFI), Vulvar Pain Functional Questionnaire (VQ), and Numeric Pain Rating Scale (NPRS). Results  Fourteen patients reported their condition pre- and postoperatively. Mean postoperative follow-up was 15 months. The overall FSFI, and arousal, lubrication, orgasm, satisfaction, and pain domains significantly improved ( p  < 0.05). The VQ also significantly improved ( p  < 0.001) in 13 (93%) of 14 patients. The NPRS score decreased on average from 8 to 3 ( p  < 0.0001). All four patients with urethral symptoms were relieved of these symptoms. Conclusion  Resection of the PBPN with implantation of the nerve into the obturator internus muscle significantly reduced pain and improved sexual function in women who sustained injury to the PBPN., Competing Interests: Conflict of Interest: None of the authors have a conflict of interest., (Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.)

Lichen sclerosus (LS) is a chronic and inflammatory disease causing sensory symptoms such as itch and pain and affecting most frequently genital skin of women. Intraepidermal nerve fiber density (IENFD) was examined immunohistologically in 20 vulvar skin biopsies of patients affected by LS and in 20 control vulvar skin biopsies, in order to determine if these sensory sensations originate in changes in the epidermal innervation. Obtained results show fewer protein gene product 9.5 (PGP 9.5) positive intraepidermal nerve fibers (IENF) in LS tissues compared to controls (P = 0.004), while the number of calcitonin gene-related peptide (CGRP) positive IENF in LS was increased compared to normal vulvar tissue (P = 0.03). No differences in the number of vasoactive intestinal peptide (VIP) expressing IENF could be observed. To our best knowledge, this is the first study to describe intraepidermal nerve fiber density in vulvar LS. Significant differences in IENFD between LS and control skin samples, which have been found, point to the damage to the small nerve fibers in the disease process of LS, which may contribute to pathogenesis of LS sensory symptoms.

Although women with vulvodynia typically have increased vulvar sensitivity, data on characteristics associated with the degree of vulvar sensitivity are lacking. We measured vulvar sensitivity using cotton swab test and vulvodolorimeter among a subset of 335 women, aged younger than 70 years, in the longitudinal Woman to Woman Health Study. Comparing the vulvodynia screening results from their online/paper survey to that at the time of the examination, 42 women had ongoing vulvodynia, 66 had a recent remission, 22 control participants had a recent onset of vulvodynia, and 205 control participants remained asymptomatic. Vulvar sensitivity was greater in each vulvodynia group compared with the control group (P < .001), and was associated with younger age at first onset of pain (P = .025), pain after intercourse (P = .008), describing the pain as a "pressure," "burning," or "irritating" (P = .015, P = .005, and P = .006, respectively), with increased severity of pain ever (P = .012), and with subsequent persistent or relapsing vulvodynia (P < .001 for each). A score of >1 for the cotton swab summary score best differentiated case from control participants (sensitivity 71.9%; specificity 72.0%). Although 13.8% of women with vulvodynia had no increased sensitivity on cotton swab testing, they did not differ in most clinical characteristics or clinical course from those with increased vulvar sensitivity., Perspective: This study showed that women with vulvodynia have more vulvar sensitivity than control women, but the spectrum of sensitivity is broad. Furthermore, those with and without vulvar sensitivity did not differ in most vulvar pain characteristics or in prognosis, suggesting a positive swab test is not required to substantiate the diagnosis., (Copyright © 2016 American Pain Society. Published by Elsevier Inc. All rights reserved.)

Background: Provoked vestibulodynia manifests as allodynia of the vulvar vestibular mucosa. The exact mechanisms that result in altered pain sensation are unknown. Recently, we demonstrated the presence of secondary lymphoid tissue, which is the vestibule-associated lymphoid tissue in the vestibular mucosa, and showed that this tissue becomes activated in provoked vestibulodynia., Objective: The purpose of this study was to examine whether expression of intraepithelial nerve fibers and nerve growth factor are related to immune activation in provoked vestibulodynia., Study Design: Vestibular mucosal specimens were obtained from 27 patients with severe provoked vestibulodynia that was treated by vestibulectomy and from 15 control subjects. We used antibodies against the protein gene product 9.5, the neuron specific neurofilament, and nerve growth factor for immunohistochemistry to detect intraepithelial nerve fibers and nerve growth factor expressing immune cells in the vestibular mucosa. For intraepithelial nerve fibers, we determined their linear density (fiber counts per millimeter of the outer epithelial surface, protein gene product 9.5) or presence (neuron specific neurofilament). Nerve growth factor was analyzed by counting the staining-positive immune cells. Antibodies against CD20 (B lymphocytes) and CD3 (T lymphocytes) were used to identify and locate mucosal areas with increased density of lymphocytes and the presence of germinal centers (ie, signs of immune activation). B-cell activation index was used to describe the overall intensity of B-cell infiltration., Results: We found more protein gene product 9.5-positive intraepithelial fibers in vestibulodynia than in the control samples (6.3/mm [range, 0.0-15.8] vs 2.0/mm [range, 0.0-12.0]; P=.006). Neuron specific neurofilament -positive intraepithelial fibers were found in 17 of 27 vestibulodynia cases (63.0%) and in none of the control cases. Protein gene product 9.5-positive intraepithelial fibers were more common in samples with more pronounced immune activation. The density of these fibers was higher in samples with than without germinal centers (6.1/mm [range, 4.3-15.8] vs 3.0/mm [range, 0.0-13.4]; P=.020). A positive correlation between the fiber density and B-cell activation index score of the sample was found (Spearman's Rho, 0.400; P=.004; R 2 =0.128). No significant difference, however, was found in the density or presence of nerve fibers between samples with high and low T-cell densities. We identified areas of minor and major vestibular glands in 16 of the patient samples and in 1 control sample. Protein gene product 9.5-positive nerve fibers were found more often in glandular epithelium surrounded by B-cell infiltration than in glands without B cells (P=.013). Also, the presence of neuron specific neurofilament-positive fibers in glandular epithelium was associated with B-cell infiltrates (P=.053). Nerve growth factor-positive immune cells were more common in mucosal areas with than without B-cell infiltration and intraepithelial nerve fibers., Conclusion: Excessive epithelial nerve growth in provoked vestibulodynia is associated with increased B-cell infiltration and the presence of germinal centers. This supports the fundamental role of immune activation in provoked vestibulodynia., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Background: Surgical techniques to alleviate labia minora hypertrophy are gaining popularity. Due to the rapidly growing number of labiaplasties performed around the world, there is concern for the safety of these procedures with respect to maintaining sensitivity to the genitalia and/or implications for sexual arousal., Objectives: An anatomic study aimed at identifying the nerve density distribution of the labia minora was performed to provide unique insight into performing labiaplasty while preserving sensation., Methods: Four fresh tissue cadaver labia minora were analyzed. Each labia minora was divided into 6 anatomic areas. The samples from each of the 6 anatomic locations were analyzed for presence of nerve bundles using both a routine hematoxylin and eosin (H&E) stain and a confirmatory immunohistochemical staining for S100 protein. Nerve density was analyzed under light microscopy, counted, and then expressed as percentage nerve density as well as number of bundles per square millimeter., Results: Upon gross analysis, the raw data reveal that labia minora have a heterogeneous population of sensory nerves. When looking at percent nerve density, the data do not reveal any statistical differences between the anatomic locations., Conclusions: Most labiaplasty techniques can be performed safely and are unlikely to cause loss of sensation as the nerve density distribution in labia minora is heterogeneous., (© 2016 The American Society for Aesthetic Plastic Surgery, Inc. Reprints and permission: journals.permissions@oup.com.)

Background: Provoked vestibulodynia is the most common form of vulvodynia. Despite its high prevalence and deleterious sexual, conjugal, and psychological repercussions, effective evidence-based interventions for provoked vestibulodynia remain limited. For a high proportion of women, significant pain persists despite the currently available treatments. Growing evidence suggests that the central nervous system (CNS) could play a key role in provoked vestibulodynia; thus, treatment targeting the CNS, rather than localized dysfunctions, may be beneficial for women suffering from provoked vestibulodynia. In this study, we aim to build on the promising results of a previous case report and evaluate whether transcranial direct-current stimulation, a non-invasive brain stimulation technique targeting the CNS, could be an effective treatment option for women with provoked vestibulodynia., Methods/design: This single-center, triple-blind, parallel group, randomized, controlled trial aims to compare the efficacy of transcranial direct-current stimulation with sham transcranial direct-current stimulation in women with provoked vestibulodynia. Forty women diagnosed with provoked vestibulodynia by a gynecologist, following a standardized treatment protocol, are randomized to either active transcranial direct-current stimulation treatment for ten sessions of 20 minutes at an intensity of 2 mA or sham transcranial direct-current stimulation over a 2-week period. Outcome measures are collected at baseline, 2 weeks after treatment and at 3-month follow-up. The primary outcome is pain during intercourse, assessed with a numerical rating scale. Secondary measurements focus on the sexual function, vestibular pain sensitivity, psychological distress, treatment satisfaction, and the patient's global impression of change., Discussion: To our knowledge, this study is the first randomized controlled trial to examine the efficacy of transcranial direct-current stimulation in women with provoked vestibulodynia. Findings from this trial are expected to provide significant information about a promising intervention targeting the centralization of pain in women with provoked vestibulodynia., Trial Registration: Clinicaltrials.gov, NCT02543593 . Registered on September 4, 2015.

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., (© 2014 Wiley Periodicals, Inc.)

Purpose: We assessed external genitalia sensitivity and sexual function in adults with congenital adrenal hyperplasia who had undergone Passerini-Glazel feminizing genitoplasty as children, and compared them to a control group of healthy counterparts., Materials and Methods: Inclusion criteria were congenital adrenal hyperplasia, Passerini-Glazel feminizing genitoplasty, adult age and penetrative vaginal intercourse. Thermal and vibratory sensitivity of the clitoris, vagina and labia minora were analyzed using the Genito Sensory Analyzer (Medoc Ltd., Minnetonka, Minnesota). Psychosexual outcome was assessed with the Beck Depression Inventory, Zung Self-Rating Anxiety Scale, Female Sexual Distress Scale and Female Sexual Function Index. Matched analyses were performed to compare outcomes in patients to controls (healthy medical students). All statistical tests were performed using SPSS®, version 18.0 RESULTS: A total of 12 patients (10%) entered the study. Thermal and vibratory clitoral sensitivity was significantly decreased in all patients compared to healthy controls (p <0.01). There was no difference in thermal or vibratory vaginal sensitivity between patients and controls. On the Female Sexual Distress Scale 11 patients (91.6%) and 11 controls (91.6%) described a stable satisfactory relationship. All patients reported active sexual desire, good arousal, adequate lubrication and orgasm. No significant difference in Female Sexual Function Index global score or single domain scores was observed between patients and controls., Conclusions: Although clitoral sensitivity in sexually active patients with congenital adrenal hyperplasia treated with Passerini-Glazel feminizing genitoplasty is significantly reduced compared to controls, sexual function in those patients is not statistically or clinically significantly different from their healthy counterparts. Finally, 1-stage Passerini-Glazel feminizing genitoplasty seems to allow normal adult sexual function., (Copyright © 2014 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.)

Introduction: The female genital sensory pathways that initiate sexual arousal reflexes begin with cutaneous corpuscular receptors in the glabrous genital skin, including those of the glans clitoris., Aim: The aim of this study is to characterize the corpuscular receptors of the glans clitoris. In addition, we compared basic features with the receptors of the glans penis., Main Outcome Measure: Number of stained receptors., Methods: Five cadaveric vulvectomy specimens and four cadaveric penile specimens were used. They were serially sectioned and stained with hematoxylin and eosin. Selected blocks were stained with Masson's trichrome, and immunohistochemical staining was done with neuronal markers S-100 and neurofilament., Results: Using the three stains, we identified an abundance of corpuscular receptors within the glans clitoris, as compared with the surrounding prepuce. These receptors were of varied arrangements, situated in the subepithelial tissues of the glans clitoris. They were indistinguishable from the receptors of the glans penis. The number of receptors per 100× high-powered field ranged from 1 to 14, whereas the receptor density in the glans penis ranged from 1 to 3. A second type of receptor, the Pacinian corpuscle, was identified within the suspensory ligament along the trunks of the dorsal nerve but not within the glans itself., Conclusions: The glans clitoris is densely innervated with cutaneous corpuscular receptors, and these receptors are morphologically similar to the corpuscular receptors of the glans penis. The glans clitoris has greater variability in receptor density compared with the glans penis., (© 2013 International Society for Sexual Medicine.)

Introduction: We present the case of a 23-year-old female with bilateral ectopic breast tissue of the vulva, the repair of which necessitated a novel labiaplasty technique. Labiaplasty is becoming an increasingly frequent cosmetic procedure, and the popularity of brief didactic labiaplasty courses has risen in response to consumer demand. There is a paucity of detailed anatomic description of female sensory innervation patterns to the clitoris and surrounding structures. This places patients at risk for denervation of clitoral structures during labiaplasty procedures. Our novel technique proposes a method of individualized patient neurosensory mapping preoperatively, which allows for surgical planning to avoid injury to the sensory branches of the dorsal clitoral nerve., Methods: A 23-year-old female presented with bilateral vulvar masses that involved the clitoral complex, which had first become apparent during the second trimester of pregnancy, and failed to resolve in the postpartum period. We describe the preoperative planning and intraoperative approach and dissection to labiaplasty in this patient, which was complex given the size of the masses, and specifically designed to avoid injury to sensory branches of the dorsal clitoral nerve., Discussion: As labiaplasty becomes more common, it is important to approach labiaplasty patients with a detailed understanding of the sensory innervation of the clitoris and surrounding structures, to avoid nerve injury and resultant sexual dysfunction. Traditional labiaplasty approaches may violate the sensory innervation patterns of the clitoral region, thus causing a sensory loss that affects patient sexual function. Our novel approach to preoperative clitoral nerve sensory mapping provides an alternative method of labiaplasty that may avoid denervation injury.

The diverse cell types and the precise synaptic connectivity between them are the cardinal features of the nervous system. Little is known about how cell fate diversification is linked to synaptic target choices. Here we investigate how presynaptic neurons select one type of muscles, vm2, as a synaptic target and form synapses on its dendritic spine-like muscle arms. We found that the Notch-Delta pathway was required to distinguish target from non-target muscles. APX-1/Delta acts in surrounding cells including the non-target vm1 to activate LIN-12/Notch in the target vm2. LIN-12 functions cell-autonomously to up-regulate the expression of UNC-40/DCC and MADD-2 in vm2, which in turn function together to promote muscle arm formation and guidance. Ectopic expression of UNC-40/DCC in non-target vm1 muscle is sufficient to induce muscle arm extension from these cells. Therefore, the LIN-12/Notch signaling specifies target selection by selectively up-regulating guidance molecules and forming muscle arms in target cells. DOI:http://dx.doi.org/10.7554/eLife.00378.001., Competing Interests: The authors declare that no competing interests exist.

Vulvar pain syndrome or vulvodynia is a common multifactorial, heterogeneous, and chronic gynecological disorder with an estimated prevalence of up to 16%. This disorder seriously impacts the quality of life of women in several ways. The etiology of this condition is complex and remains elusive and requires an extensive differential diagnosis. A standard therapeutic approach for the management of vulvar pain is still under investigation and must be multidisciplinary. This review outlines the anatomic and pathophysiologic aspects of vulvar pain., (Copyright © 2012 Wiley Periodicals, Inc.)

Background: Midurethral slings successfully treat stress urinary incontinence through a minimally invasive vaginal approach. Postoperative pain related to sling placement can occur and poses both diagnostic and treatment dilemmas., Case: Four years after transobturator midurethral sling placement, the patient presented with complaints of left labial pain and dyspareunia since surgery. Using sensory mapping and a nerve stimulator, the problem was identified in the distribution of the genitofemoral nerve. Conservative therapy with a centrally acting neuromodulatory drug and nerve block relieved the pain., Conclusion: Postsling neuralgia diagnosis using sensory mapping and a nerve stimulator aids in indentifying the nerve involved and in successful conservative treatment with a nerve block.

Study Objective: To better understand the precise role of sensory corpuscles within the female external genitalia., Design: After IRB approval, waste tissue samples were obtained from 10 normal girls (aged 2-9 years) who underwent surgery for labial fusion. Immunocytochemistry against protein gene product 9.5 (PGP 9.5), neuron-specific enolase (NSE), vasoactive intestinal peptide (VIP), 5-hydroxytryptamine transporter (5HTT), 5-hydroxytryptamine receptor 1A (5HT1A), Neuronal Peptide Y (NPY), neuronal nitric oxide synthase (nNOS), and estrogen receptors (ER) α and β was performed., Results: Pacinian-like corpuscles were identified in epithelium of labia minora of prepubertal girls. A central structure composed of an axon surrounded by a central core, outer core, external capsule, surrounded by encapsulated stroma, and a subsidiary innervation in the outer aspect of the corpuscle stroma stained for PGP 9.5 in the outer core and layers of the external capsule, NSE positive cells in layers of the outer core, 5HTT in stroma of the corpuscle and cells located in layers of the outer core, 5HT1A in cells of outer core, NPY in stroma of the corpuscle, and nNOS in external core and external capsule of the central structure. ERα was present in stroma, external core, and external capsule, and ERβ in stroma of the corpuscle with subsidiary innervation in the stroma positive to PGP 9.5, VIP, and NPY., Conclusion: PGP 9.5, NSE, ERα, nNOS, and 5HTT immunoreaction detected in the outer core and external capsule could indicate these areas may play an important role in the functional aspects of the Pacinian-like corpuscle., (Copyright © 2011. Published by Elsevier Inc.)

Provoked vestibulodynia, the most common form of vulvodynia (unexplained pain of the vulva), is a prevalent, idiopathic pain disorder associated with a history of recurrent candidiasis (yeast infections). It is characterized by vulvar allodynia (painful hypersensitivity to touch) and hyperinnervation. We tested whether repeated, localized exposure of the vulva to a common fungal pathogen can lead to the development of chronic pain. A subset of female mice subjected to recurrent Candida albicans infection developed mechanical allodynia localized to the vulva. The mice with allodynia also exhibited hyperinnervation with peptidergic nociceptor and sympathetic fibers (as indicated by increased protein gene product 9.5, calcitonin gene-related peptide, and vesicular monoamine transporter 2 immunoreactivity in the vaginal epithelium). Long-lasting behavioral allodynia in a subset of mice was also observed after a single, extended Candida infection, as well as after repeated vulvar (but not hind paw) inflammation induced with zymosan, a mixture of fungal antigens. The hypersensitivity and hyperinnervation were both present at least 3 weeks after the resolution of infection and inflammation. Our data show that infection can cause persistent pain long after its resolution and that recurrent yeast infection replicates important features of human provoked vulvodynia in the mouse.

Objective: To assess whether primary and secondary vestibulodynia represent different pathologic pathways., Methods: This was an analysis of archived vestibulectomy specimens from 88 premenopausal women with vestibulodynia (2002-2008). Patient records were reviewed to classify the type of vestibulodynia, duration of symptoms, and hormone status. Histologic sections were stained for hematoxylin and eosin to grade inflammation, S100 to highlight nerves, CD117 for mast cells, estrogen receptor α, and progesterone receptor. Differences between primary and secondary vestibulodynia were tested by t tests, chi-square analysis, and linear and logistic regression., Results: Primary vestibulodynia showed significant neural hypertrophy and hyperplasia (P=.02, adjusted odds ratio [OR] 3.01, 95% confidence interval [CI] 1.2-7.6) and increased progesterone receptor nuclear immunostaining (P=.004, adjusted OR 3.94, CI 1.6-9.9) compared with secondary vestibulodynia. Estrogen receptor α expression was also greater in primary vestibulodynia when symptom diagnosis was less than 5 years (P=.004, adjusted OR 5.53 CI 1.71-17.91)., Conclusion: Primary and secondary vestibulodynia have significantly different histologic features, suggesting that they may have separate mechanistic pathways. Clinically, this may mean the discovery of distinct conditions.

Introduction: Surgical and histologic sources of information give little reference to innervation, vascular, and epithelial details of the labia minora. Little is known about areas of nerve density, epithelial qualities, and vascular compartments of the labial minora that contribute to sexual arousal and orgasm. Surgical procedure development and counsel about surgical risks related to labioplasty and surgical flaps created from labial tissue may be based on inadequate information., Methods: Labial samples from 10 normal girls (aged 2-9 years) who underwent surgery for labial fusion utilized waste tissue strips for immunohistochemical identification of S-100 and neuronal nitric oxide synthase (nNOS) in the labia minora., Results: Vascular and lymphatic plexus lie within the reticular dermis, which contains a dense mesh of nerve fibers with a higher concentration of nerve fiber at the level of the subepithelial plexus. Dense innervations are located at the epidermis, extending along the basal and spinous layers of the epithelium of labia minora. Nerve bundles in the papillary dermis are associated with sebaceous and eccrine glands and nerve terminals located throughout the epithelium. The introital epithelium of the labia minora is highly innervated with widespread and intense staining, detected in the introital border of the labia minora versus the external one. The dermis appeared to display S-100 and nNOS immunolabelling. S-100 was also immunopositive in the epidermis., Conclusion: Labia minora is highly innervated along its entire edge. Related vascular compartment tissue involved in engorgement during sexual arousal makes this tissue important for sexual response. Labioplasty risks removal of tissue with an important contribution to sensory sexual arousal. Movement of labial tissue during genitoplasty may have different sensory outcomes dependent on which labial surface is used., (Copyright © 2010 North American Society for Pediatric and Adolescent Gynecology. Published by Elsevier Inc. All rights reserved.)

Peripheral nerves in obstetrics and gynecology are damaged with moderate frequency. Mostly there are iatrogenic lesions, that most often develop during delivery, operations and also in course of smaller invasive procedures. In genitofemoral nerve lesions neuralgic pain in groin and vulva is the most striking symptom, in cutaneous femoris lateralis nerve damage there are unpleasant paresthesias of lateral thigh. In case of femoral or obturator nerve lesion a weakness of thigh muscles with difficulties of standing and walking is the most typical. In pudendal nerve damage the autonomic disturbances (incontinence of feaces and urine) and pain in perineum are in the foreground of the patient's complains. After a knowledgeable history taking and detailed clinical examination the next step of diagnostics are neurophysiological investigations (neurography and needle electomyography). In special cases there is racional to use imaging methods (ultrasonography, MRI, CT). In majority of these iatrogennic nerve lesions the conservative approach is successful (rehabilitation, medicaments against neuropathic pain) and only in a small proportion of patients the neurosurgeon consultation is necessary.

Peptide:N-glycanases (PNGases) are cytoplasmic de-N-glycosylation enzymes that have been shown in cultured cells to facilitate the degradation of misfolded glycoproteins during endoplasmic reticulum-associated degradation and in the processing of major histocompatibility complex class I antigens for proper cell-surface presentation. The gene encoding PNGase activity was initially described in budding yeast (Png1p) and shown to be highly conserved from yeast to humans, but physiological roles in higher organisms have not been elucidated. Here we describe peripheral nervous system defects associated with the first loss-of-function mutations in an animal PNGase. Mutations in png-1, the Caenorhabditis elegans PNGase ortholog, result in an increase in axon branching during morphogenesis of the vulval egg-laying organ and egg-laying behavior changes. Neuronal defects include an increase in the branched morphology of the VC4 and VC5 egg-laying neurons as well as inappropriate branches from axons that run adjacent to the vulva but would normally remain unbranched. We show that png-1 is widely expressed and can act from both neurons and epithelial cells to restrict axon branching. A deletion allele of the DNA repair gene rad-23, orthologs of which are known to physically interact with PNGases in yeast and mammals, displays similar axon branching defects and genetic interactions with png-1. In summary, our analysis reveals a novel developmental role for a PNGase and Rad-23 in the regulation of neuronal branching during organ innervation.

Background: Pudendal neuropathy is a documented complication of sacrospinous ligament fixation, but it is infrequently reported with other types of gynecologic surgery., Case: A woman developed neuropathic symptoms of the right vulva, perianal area, and gluteal fold after vaginal surgery with graft for anterior pelvic organ prolapse. Pudendal nerve entrapment with involvement of the perforating cutaneous nerve was suspected. Suture removal 1 year after the operation resulted in improved pain symptoms and sexual function., Conclusion: Pudendal nerve entrapment is one potential complication of anterior vaginal repair with biologic graft. Removal of sutures, even long after surgery, can result in clinically significant improvement in pain symptoms and sexual function in patients with pudendal nerve entrapment.

Objective: To assess the cellular distributions of oestrogen receptors alpha and beta (ER alpha and ER beta) and neuronal nitric oxide synthase (nNOS) in the labia minora, as knowledge about ER type and function may clarify the role of oestrogens in vaginal scar formation and improve outcomes in female genital surgery., Subjects and Methods: Labial samples were taken from 10 girls (aged 2-9 years) who underwent surgery for labial fusion. The waste tissue strips obtained were used for immunohistochemical identification of ER alpha and ER beta, and nNOS in the labia minora., Results: There was ER alpha nuclear staining in the stroma of the labia minora close to the clitoris, and basal and suprabasal in the epidermal cells membrane restricted to superficial sections of the labia minora. ER beta was found in the stroma of the labia minora closer to the clitoris and in superficial sections, in the basal epidermal cells membrane and apocrine glandular epithelial cells membrane. There was also ER beta cell membrane staining in the basal and suprabasal epithelial cells and fibroblasts in the lamina propria., Conclusions: Established ER presence allows the consideration of the introitus of the vagina as a target for oestrogen therapy in various clinical and surgical situations. Continuing elucidation of the immunohistochemistry of this external genital tissue might assist in the development of molecular tools to treat genital abnormalities. Details of this immunohistochemistry may also advance the understanding of the effects of sexual differentiation on the brain and other organ systems.

In the free-living nematode Caenorhabditis elegans, cilia are found on the dendritic endings of sensory neurons. C. elegans cilia are classified as 'primary' or 'sensory' according to the '9+0' axonemal ultrastructure (nine doublet outer microtubules with no central microtubule pair) and lack of motility, characteristics of '9+2' cilia. The C. elegans ciliated nervous system allows the animal to perceive environmental stimuli and make appropriate developmental, physiological, and behavioral decisions. In vertebrates, the biological significance of primary cilia had been largely neglected. Recent findings have placed primary/sensory cilia in the center of cellular signaling and developmental processes. Studies using genetic model organisms such as C. elegans identified the link between ciliary dysfunction and human ciliopathies. Future studies in the worm will address important basic questions regarding ciliary development, morphogenesis, specialization, and signaling functions.

Objective: To carry out a critical review of published studies concerning the treatment of provoked vestibulodynia., Methods: MEDLINE, PsycINFO, and Cochrane were used to identify treatment studies published between January 1996 and December 2006. All studies published in English that dealt specifically with the treatment of provoked vestibulodynia were included in the review regardless of their methodological quality. Thirty-eight treatment studies were thus examined in the present paper., Results: Since 1996, surgical treatment has received somewhat less empirical attention. Nevertheless, it still boasts the best success rates, which range from 61% to 94%. More studies have focused on medical treatments, yielding success rates varying between 13% and 67%. Behavioral treatments have been the least studied, although 35% to 83% of patients benefit from them. Despite these interesting results, only 5 of the 38 treatment studies reviewed are randomized clinical trials. Furthermore, the majority of studies have several methodological weaknesses, such as the absence of (1) control or placebo group, (2) double-blind evaluation, (3) pretreatment pain evaluation, and (4) validated measures of pain and sexual functioning., Discussion: On the basis of the results of the reviewed prospective studies and the randomized clinical trials, vestibulectomy is the most efficacious treatment to date. Though some medical treatments seem little effective, others appear promising and should be investigated further, as is the case with behavioral treatments. Additional randomized clinical trials are necessary to confirm the efficacy of surgery and validate nonsurgical treatments for provoked vestibulodynia.

Introduction: Vulvodynia is increasingly recognized as a cause of sexual pain. Aim. The goal of this Continuing Medical Education article was to provide a comprehensive review of vulvodynia including terminology, possible etiologies, and offer treatment options., Methods: A Medline search was conducted using several terms related to and including the terms vulvodynia, vulvar vestibulitis, vestibulodynia, and pudendal neuralgia., Results: A thorough review of vulvodynia., Conclusion: Vulvodynia most likely represents several disorders without an identifiable cause in many cases. The management of these patients requires a sensitive provider who can coordinate a multidisciplinary approach to their care. Despite the lack of large-scale, placebo-controlled trials, several new treatment options exist.

Recently, we have shown that vestibular hyperinnervation and the presence of 8 or more mast cells in a 10 x 10 microscopic field can be used as diagnostic criteria in localized vulvodynia (vulvar vestibulitis). We have also documented that degranulation of mast cells occurs in these cases. The present study further examines the characteristics of vestibular hyperinnervation and mast cell function in localized vulvodynia to elucidate if the 2 processes-hyperinnervation and mast cell increase and degranulation-are related. We examined vestibular tissue from 7 women aged 18 to 48 with severe localized vulvodynia and from 7 healthy control women. Parallel sections were stained by Giemsa and then immunostained for CD117 and heparanase. Nerve fibers that expressed protein gene product 9.5 were examined. Tissues from women with localized vulvodynia documented a significant increase in vestibular mast cells, subepithelial heparanase activity, and intraepithelial hyperinnervation compared with healthy women. This is the first documentation of heparanase activity in localized vulvodynia. Heparanase, which is degranulated from mast cells, is capable of degrading the vestibular stroma and epithelial basement membrane, thus permitting stromal proliferation and intraepithelial extension of nerve fibers, as seen in the present study. The hyperinnervation has been thought to cause the vestibular hyperesthesia distinctive of localized vulvodynia.

Netrin is an evolutionarily conserved axon guidance molecule that has both axonal attraction and repulsion activities. In Caenorhabditis elegans, Netrin/UNC-6 is secreted by ventral cells, attracting some axons ventrally and repelling some axons, which extend dorsally. One axon guided by UNC-6 is that of the HSN neuron. The axon guidance process for HSN neurons is complex, consisting of ventral growth, dorsal growth, branching, second ventral growth, fasciculation with ventral nerve cords, and then anterior growth. The vulval precursor cells (VPC) and the PVP and PVQ neurons are required for the HSN axon guidance; however, the molecular mechanisms involved are completely unknown. In this study, we found that the VPC strongly expressed UNC-6 during HSN axon growth. Silencing of UNC-6 expression in only the VPC, using a novel tissue-specific RNAi technique, resulted in abnormal HSN axon guidance. The expression of Netrin/UNC-6 by only the VPC in unc-6 null mutants partially rescued the HSN ventral axon guidance. Furthermore, the expression of Netrin/UNC-6 by the VPC and the ventral nerve cord (VNC) in unc-6 null mutants restored the complex HSN axon guidance. These results suggest that UNC-6 expressed by the VPC and the VNC cooperatively regulates the complex HSN axon guidance.

The relationship between sexual arousal and sensory perception has been a topic largely neglected within the realm of human sexuality research. The present study assessed the influence of sexual arousal on genital and non-genital sensation in women. It also examined the theory that painful intercourse is associated with insufficient sexual arousal. A total of 20 healthy women and 20 women with Vulvar Vestibulitis Syndrome (VVS) underwent genital and non-genital sensory testing at baseline and in response to erotic and neutral stimulus films. Touch and pain thresholds were assessed at the vulvar vestibule, inside the labia minora, and on the volar surface of the forearm. Sexual arousal was assessed via the measurement of surface skin temperature changes of the labia minora using a labial thermistor clip. Participants also completed questionnaires pertaining to mood, pain, and sexual functioning. In response to the erotic stimulus, both groups evidenced a significant increase in physiological sexual arousal and vulvar sensitivity. Women with VVS reported a significantly lower desire to engage in intercourse after having viewed the erotic film and reported lower levels of desire and arousal on questionnaire measures. Women with VVS also exhibited significantly more genital and non-genital pain sensitivity than healthy women across all conditions, in addition to more catastrophizing, hypervigilance, and fear of pain. Contrary to some theories, these data suggest that women with VVS are not lacking in physiological sexual arousal, and that physiological sexual arousal may actually increase vulvar sensation. Lack of subjective sexual arousal, however, may yet be implicated in vulvar pain during intercourse.

Objective: To investigate the microanatomic basis of the pudendal-thigh flap and provide the anatomic basis for clinical application., Methods: Skin microdissection of the pudendal regions was performed on 11 adult cadavers (22 sides). Then, the clinical way was simulated to obtain the flaps, and the vessels and nerves contained in them were surveyed. After that, the tissues in the deep part were dissected, and the vessels and nerves were traced back to their origins. The notes were taken., Results: The blood supply to the pudenal regions was plentiful and constant. The initiation point of the superficial external pudendal artery was 2.14+ 0.23 mm in diameter; one branch of it was the inguinal branch and the other branch was the perineal branch. Their diameters were 1.38+0.34 mm and 1.21+0.24 mm. The initiation point of the posterior labial or scrotum arteries was 1.13+ 0.24 mm in diameter, and the lateral branch was 0. 67+0. 33 mm in diameter. The anterior cutaneous branch of the obturator artery was 1.68+ 0.11 mm in diameter. The position of all the blood vessels was relatively constant, especially the external pudendal artery and the lateral branch of the posterior scrotal artery. Many of the blood vessels passed through the areas of the pudendum and the thigh, anastomosed with each other. Three groups of the vascular net passed through the upper, middle and lower parts of the flap. Three main groups of the innervation were as the following: the ramus femoralis nervi genitofemoralis, the cutaneous branches of the ilioinguinal nerve, and the post-nerve of the scrotum or the labia vulvae., Conclusion: The pudendal-thigh flap has an abundant blood supply, and its dissection is convenient with an easy incision; the donor site is covert. The pudendal-thigh skin flap has the following advantages for the sexual organ reconstruction: the skin flap can have a good sensation and a good shape, and the operative procedure is easy to perform.

Introduction: Vulvar vestibulitis syndrome (VVS) is a common cause of vulvar pain. Therapeutic options target different pain systems believed to be involved in its development and maintenance. Most treatments target the pain component with the assumption that sexual function will increase once the pain has decreased, yet this is not necessarily the case., Aims: Research has supported the effectiveness of hypnosis for many chronic pain disorders, and a case report demonstrated pain reduction and an increase in intercourse pleasure in a woman with VVS. This preliminary study examined the effectiveness of hypnosis on pain and psychosexual function in VVS. METHODS; Eight women suffering from VVS completed a hypnosis screening assessment, an interview, pain and psychosexual questionnaires, a gynecologic examination, vestibular pain threshold measurement, a psychosexual assessment, and six hypnotherapy sessions. The physical examinations, interview, and questionnaires were repeated at 1 and 6 months posttreatment., Main Outcome Measures: These included pain ratings during the gynecologic examination, vestibular pain thresholds, scores on the McGill Pain Questionnaire and Pain Catastrophizing Scale, and responses to questions on intercourse-related and nonintercourse-related pain. Measures of psychosexual function included the Female Sexual Function Index, State-Trait Anxiety Scale, Beck Depression Inventory-II, and the Brief Symptom Inventory., Results: Results indicated significant decreases in gynecologic examination pain and in several measures assessing intercourse pain, and nonsignificant increases in threshold. Some indices of noncoital vulvar pain decreased. Overall sexual function, particularly sexual satisfaction, increased at posttreatment. There were no differences on any psychological measure. Participants reported satisfaction with the treatment and rated their VVS pain reduction as average., Conclusions: Hypnotherapy appears to be a promising treatment for reducing intercourse pain and some aspects of noncoital vulvar pain, and for restoring sexual function in women with VVS. These results suggest that a large controlled trial should be considered.

Fifty-three women with partial vaginismus with or without vulvar vestibulitis and 27 asymptomatic women estimated sensations of burning pain and itch at 20 standardized moments during a standardized penetration situation, including vaginal muscle contractions. Forty-three women with partial vaginismus (81.1%) reported burning pain, 23 (43.4%) itch, and 22 (41.5%) both complaints, compared to 0% of the asymptomatic women. In 17 of 22 cases, burning pain preceded the appearance of itch and in four cases the two complaints coincided. The median time from the moment when burning pain started until itch appeared was 150 seconds.

Naked mole-rats live in large colonies and exhibit a strict reproductive hierarchy. Each colony has one breeding female and one to three breeding males; all other individuals are nonreproductive subordinates. Subordinates show a remarkable lack of sex differences in behavior and anatomy, but can become reproductive if removed from the colony. We recently reported that the striated perineal muscles and their innervating motoneurons, which are sexually dimorphic in all other mammals examined to date, are not dimorphic in subordinate naked mole-rats. Here we asked whether sexual differentiation of this neuromuscular system occurs when a subordinate becomes a breeder. The size and number of cells within Onuf's nucleus (homologue of the rat spinal nucleus of the bulbocavernosus) as well as perineal muscle volume were examined in subordinate and breeding naked mole-rats of both sexes. Sex differences in perineal motoneurons were not observed, regardless of social status. To our surprise, however, counts of motoneurons in Onuf's nucleus were increased approximately 30% in breeders of both sexes. This was accompanied by a reciprocal decrease in cells in Onuf's nucleus that were characterized by small soma size, and lacked a clear nucleus or nucleolus. Although not exhibiting typical motoneuron morphology, some of these small cells were positive for the motoneuron marker, SMI-32. The neuronal changes correlate with increased perineal muscle volumes in breeders. We propose that small, relatively undifferentiated cells are recruited to the pool of large Onuf's nucleus motoneurons when subordinate naked mole-rats become breeders., ((c) 2006 Wiley Periodicals, Inc.)

Purpose: The initiation of genital tactile stimulation is regarded as a precursor to sexual arousal and perhaps in women it is the most easily recognized initiator of central nervous system arousal. Unfortunately little published material details the specific mechanisms preceding arousal, beginning at the epithelial level, which are the sensory precursors to arousal. Little is known about its cutaneous receptors, nerves and the other histochemical properties of this epithelial tissue that contribute to sexual arousal. Sexual sensitivity evaluations target female genital somatosensory pathways for cutaneous sensation by testing evoked potentials of nerves, hot/cold and vibratory sensory discrimination. The anatomical bases of these several sensibilities form a subject for future investigation. We reviewed the known influences and mechanisms responsible for the arousing properties of the epithelium in the female external genitalia as well neural pathways associated with sexual arousal originating from the vulvar epithelium., Materials and Methods: A comprehensive review was done of published, relevant clinical and histological material in human and nonhuman vertebrate studies., Results: Tactile stimulation of the vulvar epithelium initiates changes suggesting complex integrative mechanisms. Influences of skin temperature, hormonal environment, mechanical tissue compliance and inflammation as well as the large number of transmitters and neuropeptides involved in peripheral pathways serving female sexual arousal speak of a direct sensory role., Conclusions: Genital epithelial cells may actively participate in sensory function to initiate sexual arousal by expressing receptors and releasing neurotransmitters in response to stimuli, resulting in epithelial-neuronal interactions.

C. elegans hermaphrodites are self-fertile, and their rate and temporal pattern of egg-laying are modulated by diverse environmental cues. Egg-laying behavior has served as an important phenotypic assay for the genetic dissection of neuronal signal transduction mechanisms. This chapter reviews our current understanding of the neuronal and neurochemical mechanisms underlying the control of egg-laying in C. elegans. The roles of specific neurons in the egg-laying motor circuit, which release multiple neurotransmitters affecting distinct parameters of egg-laying muscle activity, and the possible mechanisms for sensory control of egg-laying behavior, are discussed.

This study assessed the association between pain perception and psychological variables in women with vulvar vestibulitis syndrome (VVS) by comparing 28 VVS women with 50 healthy women. We assessed non genital systemic pain perception with quantitative sensory testing by administering experimental pain stimuli to the forearm. The VVS women demonstrated a lower pain threshold and a higher magnitude estimation of pain, combined with a higher trait anxiety, increased somatization, and a lower body image. Among the VVS women, nonvaginal pain catastrophizing was significantly related to reported pain during coitus. A cluster analysis revealed four subtypes of VVS women, as characterized by levels of pain and personality variables. I suggest implications for the assessment and treatment of women suffering from painful coitus.

Using the Female Sexual Function Index (FSFI; Rosen et al., 2000), we assessed forty-two women with vulvodynia. Internal consistency was high (Cronbach's alphas = 0.90-0.97) for all scales. We compared scale scores to published healthy and patient sample data and found very large effect sizes (1.15-2.83), which indicated that women with vulvodynia reported significantly worse overall sexual function than women without sexual dysfunction and greater pain with sexual intercourse than women with female sexual arousal disorder. Results highlight difficulties experienced across all domains of sexual function, particularly with regard to dyspareunia, for women with vulvodynia. Findings also support the internal consistency and discriminant validity of the FSFI.

Vulvar vestibulitis syndrome (VVS) is a heterogeneous, multisystemic, and multifactorial disease and is one of the leading causes of dyspareunia in fertile women. As a multisystemic disease, it involves the mucous structure of the vulvar vestibule and the immune, muscular, vascular, and nervous systems, including pain fibers and centers. As a multifactorial disease, its etiology is complex, involving biological, psychosexual, and relational factors. In this article, we discuss the progression of the disease and the impact of an often lengthy delay between the onset of symptoms and a correct diagnosis. Moreover, despite documented improvements from available treatments, VVS becomes a chronic disease unless it is diagnosed early and an integrated, pathophysiologically oriented treatment is offered in an experienced center. Health care providers would therefore benefit from approaching the condition within a pain management framework focused on the woman's chronic pain, the impact on the couple's relationship, and any associated psychological sequelae.

Vulvodynia is characterised by painful burning sensation, allodynia and hyperalgesia in the region of the vulval vestibulus. While in many patients the cause of vulvodynia remains uncertain, we and others have previously shown increased intraepithelial and papillary innervation in vulvodynia. The vanilloid receptor VR1 (TRPV1) is expressed by nociceptors, and is triggered by capsaicin, noxious heat, protons, and chemicals produced during inflammation. In the present study we show increased papillary VR1 fibres by immunostaining and image analysis in vulvodynia tissues compared to controls (p<0.002). VR1 expression was found to be significantly increased when the percentage area immunostained was expressed as a ratio of VR1 to PGP 9.5, a pan-neuronal marker (P=0.01). VR1-positive fine epidermal fibres also appeared to be increased in vulvodynia tissues, by inspection. Fibres immunoreactive to the voltage-gated sodium channel SNS1/PN3 (Nav1.8), also expressed by nociceptors, were relatively scarce in both vulvodynia and control tissues. We hypothesize that increased expression of VR1 by nociceptors could mediate some of the symptoms in vulvodynia, for which systemic or topical specific VR1 antagonists may provide novel treatment.

Objective: Vestibulitis is currently diagnosed based only on clinical criteria. To achieve histopathological diagnostic criteria, we carried out a computerized image analysis method., Methods: Vestibular tissues removed from 40 women with severe vestibulitis were immunostained for mast cell count and degranulation by C-kit and mast cell tryptase, respectively. Vestibular nerve cells total area was evaluated after S-100 stain. Controls were 7 women aged 18-48. The images were converted to a digital signal, and analyzed using Image Proplus V4 software., Results: We found a significant increase in inflammatory infiltrate, number of mast cells and degranulated mast cells in vestibulitis compared to normal controls. The inflammatory cells were localized around the superficial minor vestibular glands. The total nerve fiber area was ten times higher in vestibulitis patients than in controls. A significant positive correlation was found between the total nerve fiber area and the number of mast cells in the vestibulitis group of patients., Conclusion: We documented two diagnostic histopathological criteria for vestibulitis: (1) the presence of eight or more mast cells per 10 x 10 microscopic field, and (2) the total calculated area of the nerve fibers is ten times higher than expected. These findings re-establish the inflammatory nature of the vestibulitis. It is speculated that the trigger for the local outburst of nerve fibers could be related to the activation of the mast cells by a topical agent., (Copyright (c) 2004 S. Karger AG, Basel.)

egl-30 encodes the single C. elegans ortholog of vertebrate Galphaq family members. We analyzed the expression pattern of EGL-30 and found that it is broadly expressed, with highest expression in the nervous system and in pharyngeal muscle. We isolated dominant, gain-of-function alleles of egl-30 as intragenic revertants of an egl-30 reduction-of-function mutation. Using these gain-of-function mutants and existing reduction-of-function mutants, we examined the site and mode of action of EGL-30. On the basis of pharmacological analysis, it has been determined that egl-30 functions both in the nervous system and in the vulval muscles for egg-laying behavior. Genetic epistasis over mutations that eliminate detectable levels of serotonin reveals that egl-30 requires serotonin to regulate egg laying. Furthermore, pharmacological response assays strongly suggest that EGL-30 may directly couple to a serotonin receptor to mediate egg laying. We also examined genetic interactions with mutations in the gene that encodes the single C. elegans homolog of PLCbeta and mutations in genes that encode signaling molecules downstream of PLCbeta. We conclude that PLCbeta functions in parallel with egl-30 with respect to egg laying or is not the major effector of EGL-30. In contrast, PLCbeta-mediated signaling is likely downstream of EGL-30 with respect to pharyngeal-pumping behavior. Our data indicate that there are multiple signaling pathways downstream of EGL-30 and that different pathways could predominate with respect to the regulation of different behaviors.

From nematodes to humans, animals employ neuromodulators like serotonin to regulate behavioral patterns and states. In the nematode C. elegans, serotonin has been shown to act in a modulatory fashion to increase the rate and alter the temporal pattern of egg laying. Though many candidate effectors and regulators of serotonin have been identified in genetic studies, their effects on specific neurons and muscles in the egg-laying circuitry have been difficult to determine. Using the genetically encoded Ca(2+) indicator cameleon, we found that serotonin acts directly on the vulval muscles to increase the frequency of Ca(2+) transients. In contrast, we found that the spontaneous activity of the egg-laying motorneurons was silenced by serotonin. Mutations in G protein alpha subunit genes altered the responses of both vulval muscles and egg-laying neurons to serotonin; specifically, mutations in the G(q)alpha homolog egl-30 blocked serotonin stimulation of vulval muscle Ca(2+) transients, while mutations in the G(o)alpha homolog goa-1 prevented the silencing of motorneuron activity by serotonin. These data indicate that serotonin stimulates egg laying by directly modulating the functional state of the vulval muscles. In addition, serotonin inhibits the activity of the motorneurons that release it, providing a feedback regulatory effect that may contribute to serotonin adaptation.

Neuronal axons connect to multiple target cells through the formation of collateral branches, but the mechanisms that regulate this process are largely unknown. We show that BAM-2, a neurexin-related transmembrane protein, is required for development of VC motoneuron branches in the worm Caenorhabditis elegans. Expression analysis and ectopic expression experiments suggest that BAM-2 functions as a branch termination cue and reveal a mechanism for selective control of branches that sprout off a primary axon.

Background: Vulval vestibulitis is a condition characterized by the sudden onset of a painful burning sensation, hyperalgesia, mechanical allodynia, and occasionally pruritus, localized to the region of the vulval vestibulus. It is considered the commonest subset of vulvodynia. Pain precipitated in the absence of nociceptor stimuli might be triggered by previous peripheral nerve injury, or by the release of neuronal mediators, which set off inappropriate impulses in nonmyelinated pain fibres sensitizing the dorsal horn neurones. The pathophysiology of vulval vestibulitis is still unclear., Objectives: The objective of this study was to evaluate the nerve fibre density and pattern, in specimens of vulval vestibulus, in normal subjects and in patients with vestibulitis, and provide objective diagnostic criteria for this condition. Methods Twelve patients with a history of the vestibulitis type of vulvodynia, and eight normal subjects underwent biopsy of the posterior wall of the vulval vestibule. Quantitative immunohistochemistry was performed, using antisera to the general neuronal marker protein gene product (PGP) 9.5, and to the neuropeptide calcitonin gene-related peptide (CGRP), on 15- microm sections., Results: There was a statistically significant increase of density and number of PGP 9.5 immunoreactive in the papillary dermis of patients with vulvodynia of the vestibulitis type, compared with those of controls. However, the distribution pattern of the innervation showed no significant change. There were no significant differences in CGRP staining between patients and controls., Conclusions: It is concluded that the increase of PGP 9.5 immunoreactive nerve fibres, in patients with vulvodynia, may be either secondary to nerve sprouting, or may represent neural hyperplasia. Increased innervation may be applied as an objective diagnostic finding in vulval vestibulitis syndrome.

During nervous system development, neurons form reproducible synapses onto specific targets. Here, we analyze the development of stereotyped synapses of the C. elegans HSNL neuron in vivo. Postsynaptic neurons and muscles were not required for accurate synaptic vesicle clustering in HSNL. Instead, vulval epithelial cells that contact HSNL act as synaptic guidepost cells that direct HSNL presynaptic vesicles to adjacent regions. The mutant syg-1(ky652) has defects in synapse formation that resemble those in animals that lack vulval epithelial cells: HSNL synaptic vesicles fail to accumulate at normal synaptic locations and form ectopic anterior clusters. syg-1 encodes an immunoglobulin superfamily protein that acts in the presynaptic HSNL axon. SYG-1 protein is localized to the site of future synapses, where it initiates synapse formation and localizes synaptic connections in response to the epithelial signal. SYG-1 is related to Drosophila IrreC and vertebrate NEPH1 proteins, which mediate cell-cell recognition in diverse developmental contexts.