Persistent genital arousal disorder - the present knowledge. / Zespól przetrwalego pobudzenia genitalnego ­ aktualny stan wiedzy.

Persistent genital arousal disorder (PGAD) is a relatively recently described sexual disorder, characterized by symptoms of spontaneous genital arousal which persist in the absence of sexual desire and may affect women and men. Epidemiological studies conducted so far indicate that the prevalence of PGAD in the population may reach 1-4%. The etiology of PGAD remains unclear and complex, hypothesized causes include vascular, neurological, hormonal, psychological, pharmacologic, dietary, mechanical factors or a combination of these factors. Proposed methods of treatment include pharmacotherapy, psychotherapy, electroconvulsive therapy, hypnotherapy, injection of botulinum toxin, pelvic floor physical therapy, application of anesthetizing agents, reduction of identifiable factors exacerbating the symptoms, and transcutaneous electrical nerve stimulation. There is no standardized treatment algorithm for PGAD due to lack of clinical trials (evidence-based medicine). The classification of PGAD is under discussion: it could be classified as a separate sexual disorder, a subtype of vulvodynia or a disorder with pathogenesis similar to overactive bladder (OAB) and restless legs syndrome (RLS). Due to specificity of symptoms, patients may feel shame and discomfort during the examination or even delay reporting symptoms to the specialist. Thus, it is crucial to spread knowledge about this disorder, which would allow doctors to diagnose and help PGAD patients sooner.

Laser-Evoked Potentials to Pudendal Stimulation in Healthy Subjects: A Pilot Study.

PURPOSE: Laser-evoked potentials (LEPs) are useful neurophysiological tools for investigating the A-delta sensory peripheral fibers and the central nociceptive pathway. The current investigation aims to obtain normative values of LEPs via pudendal nerve stimulation in healthy adult volunteers. METHODS: Laser-evoked potentials were recorded in 16 men and 22 women, 22 to 75 years of age, using neodymium and yttrium and aluminum and perovskite laser bilateral stimulation to the pudendal nerve-supplied skin and the dorsal surface of the hands and feet. We assessed the perceptive threshold, latency, and amplitude of the N1 component and main vertex N2-P2 complex. The relationship between gender, age, height, and site of stimulation was statistically analyzed. RESULTS: Both in men and in women, laser perceptive threshold increased from genitalia to foot and from hand to foot (P ≤ 0.001). N1 and N2-P2 latencies progressively increased from pudendal area to hand to foot (P ≤ 0.008). N1 and N2-P2 complex LEP amplitudes progressively decreased from hand to genitalia to foot (P ≤ 0.04). The latencies of N1 component and N2-P2 complex of LEPs correlated with body height, whereas the amplitude of the N2-P2 complex correlated negatively with age; no correlations were observed between the latencies and amplitudes with gender. CONCLUSIONS: This study provides normative data on pudendal LEPs versus hand and foot LEPs. Incorporation of pudendal LEPs into clinical practice could provide a valuable neurophysiological tool for the study of pelvic pain syndromes.

Persistent Genital Arousal Disorder: Review of Pertinent Peripheral Nerves.

INTRODUCTION: Persistent genital arousal disorder (PGAD) is a condition that is still poorly understood. Etiologies reported for PGAD are vascular, neurological, pharmacological, and psychological. Determining the neurophysiological etiology of PGAD began with developing an understanding of the underlying biomechanics of the pudendal nerve and the female sexual response. AIM: To summarize the anatomy, physiology, etiologies, diagnostics, and treatments of the pertinent peripheral nerves involved in the pathology of PGAD. METHODS: We performed a PubMed, Cochrane, Embase, Web of Science, and Google Scholar search for English-language articles in peer-reviewed journals with no predefined time period for inclusion. Terms included "humans"[All Fields] AND "persistent"[All Fields] AND/OR ("genitalia"[All Fields] OR "genital"[All Fields]) AND/OR "arousal"[All Fields] AND/OR ("disease"[All Fields] OR "disorder"[All Fields]) AND/OR "nerve"[All Fields]. The main outcomes of the papers were reviewed. MAIN OUTCOME MEASURE: The main outcome measures were the anatomy and physiology, etiologies, history and physical examination, diagnostic imaging, and current evidence for the treatment of PGAD related to the peripheral nervous system. RESULTS: Most of the literature for PGAD originates from case studies. The diagnosis of PGAD itself is still a debated topic of discussion. More recent data published indicate that this disease affects males, as well. CONCLUSION: Nerve entrapment may be a source of continuous arousal. Associated PGAD symptoms would depend on the segment of the nerve involved. Unwelcomed or unwanted arousal has been observed as the most common detrimental symptom. Pelvic 3-tesla magnetic resonance imaging is recommended in all patients with suspected nerve entrapment. Lumbosacral 3-tesla magnetic resonance imaging is recommended if a Tarlov cyst or a herniated intervertebral disc is suspected. If the peripheral nerve is the source of the pathology, surgical intervention may be curative. A multidisciplinary team approach consisting of a medical provider, pelvic floor physical therapist, and sex therapist has demonstrated benefits. There are currently no Food and Drug Administration-approved evidenced-based treatments for PGAD. Klifto KM, Dellon AL. Persistent Genital Arousal Disorder: Review of Pertinent Peripheral Nerves. Sex Med Rev 2020;8:265-273.

Role of MR Neurography in Groin and Genital Pain: Ilioinguinal, Iliohypogastric, and Genitofemoral Neuralgia.

OBJECTIVE: Chronic neuralgia of the border nerves (ilioinguinal, iliohypogastric, and genitofemoral) is difficult to diagnose and treat clinically. We examined the role of MR neurography (MRN) in the evaluation of border nerve abnormalities and the results of treatments directed at the MRN-detected nerve abnormalities. MATERIALS AND METHODS: This retrospective cross-sectional study included 106 subjects with groin or genital pain (mean [± SD] age, 50.7 ± 15.4 years) who showed mono- or multifocal neuropathy of the border nerves at 3-T MRN. Subjects who underwent CT-guided perineural injection were assessed for pain response. Injection responses were categorized as positive, possible positive, and negative. Subjects who received hyaluronidase, continuous radiofrequency ablation, or surgery were also evaluated for treatment outcomes. RESULTS: One hundred forty abnormal nerves were positive for neuropathy in 106 studies. Eighty of 106 subjects had single neuropathy, and 26 had multifocal neuropathy. Fifty-eight subjects underwent CT-guided perineural injections, with five receiving bilateral injections (63 injections). Improvement in subjective pain was seen in 53 of 63 cases (84.2%). A statistically significant improvement in pain response was noted in the isolated ilioinguinal nerve block group as compared with the isolated genitofemoral nerve block group (p = 0.0085). Thirteen of 58 subjects received multiple nerve injections at the same sitting. Both groups receiving single or multiple nerve injections had similar improvement in pain scores of 84% and 85%, respectively, although this difference was not statistically significant. CONCLUSION: Our retrospective analysis showed improved pain relief in subjects who underwent CT-guided nerve blocks on the basis of a positive MRN.

Revisiting the genital and femoral branches of the genitofemoral nerve: Suggestion for a more accurate terminology.

The genitofemoral nerve is a branch of the lumbar plexus originating from the ventral rami of the first and second lumbar spinal nerves. During routine dissections of this nerve, we have occasionally observed that the genital branch of the genitofemoral nerve gave rise to the femoral branch, and the femoral branch of the genitofemoral nerve gave rise to the genital branch. Therefore, this study aimed to investigate the aforementioned distributions of the genitofemoral nerve in a large number of cadaveric specimens. Twenty-four sides from fourteen fresh-frozen cadavers derived from nine males and five females were used in this study. For proximal branches of the genitofemoral nerve, that is, as they first arise from the genitofemoral nerve, the terms "medial branch" and "lateral branch" were used. For the final distribution, the terms "genital branch" and "femoral branch" were used. On eight sides (33.3%) with nine branches, one or two branch(s) from either the medial or lateral branch became coursed as the femoral or genital branches (five became femoral and four became genital branches). Our study revealed that the distribution of the genitofemoral nerve is more complicated than previously described. The "medial branch" and "lateral branch" that we have used in the present study for describing the proximal branches of the genitofemoral nerve are more practical terms to describe the genitofemoral nerve. Clin. Anat. 32:458-463, 2019. © 2019 Wiley Periodicals, Inc.

Genital Sensations in Persistent Genital Arousal Disorder: A Case for an Overarching Nosology of Genitopelvic Dysesthesias?

INTRODUCTION: Persistent genital arousal disorder (PGAD) is a highly distressing and poorly understood condition characterized by unwanted sensations of genital arousal in the absence of subjective sexual desire. Research has shown that some individuals with PGAD also report orgasm, urinary, and pain symptoms, with 1 recent study specifically comparing a "painful persistent genital arousal symptom" group to a "non-painful persistent genital arousal symptom" group on various indicators given the highly frequent report of comorbid genitopelvic pain in their sample. AIM: To review literature on PGAD focusing on the presence of pain symptoms. METHODS: A literature review through May 2018 was undertaken to identify articles that discuss pain characteristics in individuals with persistent sexual arousal syndrome, persistent genital arousal disorder, symptoms of persistent genital arousal, and restless genital syndrome. MAIN OUTCOME MEASURE: A review of pain/discomfort associated with persistent genital arousal, and the proposal of a new theoretical framework of genitopelvic dysesthesias. RESULTS: PGAD is a distressing condition that is associated with a significant, negative impacts on psychosocial and daily functioning. Although it is clear that unwanted and persistent genital arousal is the hallmark symptom of PGAD, symptoms of pain and discomfort are also frequently reported. Based on the results of this review, a model of genitopelvic dysesthesias is proposed, with subcategories of unpleasant sensations that are based on patients' primary complaint: arousal, arousal and pain, or pain (and other sensations). CONCLUSION: The proposed model can provide an important framework for conceptualizing conditions characterized by unpleasant genitopelvic sensations. A model such as this one can benefit highly misunderstood conditions that are questioned in terms of their legitimacy and severity-such as PGAD-by conceptualizing them as sensory disorders, which in turn can reduce stigma, unify research efforts, and potentially improve access to care. Pukall CF, Jackowich R, Mooney K, et al. Genital Sensations in Persistent Genital Arousal Disorder: A Case for an Overarching Nosology of Genitopelvic Dysesthesias? Sex Med Rev 2019;7:2-12.

At-home genital nerve stimulation for individuals with SCI and neurogenic detrusor overactivity: A pilot feasibility study.

OBJECTIVE: Neurogenic bladder dysfunction, including neurogenic detrusor overactivity (NDO) is one of the most clinically significant problems for persons with spinal cord injury (SCI), affecting health and quality of life. Genital nerve stimulation (GNS) can acutely inhibit NDO-related reflex bladder contractions and increase bladder capacity. However, it is unknown if GNS can improve urinary continence or help meet individuals' bladder management goals during sustained use, which is required for GNS to be clinically effective. DESIGN: Subjects maintained voiding diaries during a one-month control period without stimulation, one month with at-home GNS, and one month after GNS. Urodynamics and quality of life assessments were conducted after each treatment period, and a satisfaction survey was taken at study completion. SETTING: Subject screening and clinical procedures were conducted at the Louis Stokes Cleveland VA Medical Center. Stimulation use and voiding diary entries were conducted in subjects' homes. PARTICIPANTS: Subjects included five men with SCI and NDO. INTERVENTIONS: This study tested one month of at-home portable non-invasive GNS. OUTCOME MEASURES: The primary outcome measure was leakage events per day. Secondary outcome measures included self-reported subject satisfaction, bladder capacity, and stimulator use frequency. RESULTS: GNS reduced the number of leakage events from 1.0 ± 0.5 to 0.1 ± 0.4 leaks per day in the four subjects who reported incontinence data. All study participants were satisfied that GNS met their bladder goals; wanted to continue using GNS; and would recommend it to others. CONCLUSIONS: Short term at-home GNS reduced urinary incontinence and helped subjects meet their bladder management goals. These data inform the design of a long-term clinical trial testing of GNS as an approach to reduce NDO.

Physiological and Anatomical Outputs of Rat Genital Cortex.

Rat somatosensory genital cortex contains a large sexually monomorphic representation of the penis in males and the clitoris in females. Genital cortex microstimulation-evoked movements of legs, trunk and genitals, which showed sex-specific differences related to mating behaviors and included thrusting in males and lordosis-like movements in females. Erections/tumescence of penis or clitoris could not be evoked, however. Anterograde tracer injections into penis/clitoris cortex revealed eleven corticocortical and 10 subcortical projection targets, which were qualitatively similar in both sexes. Corticocortical genital-cortex-projections innervated about 3% of the cortical surface and most were analog to other somatosensory projections targeting motor cortex, secondary somatosensory cortex, parietal cortex and perirhinal cortex. Corticocortical projections that differed from other parts of somatosensory cortex targeted male scrotum cortex, female vulva cortex, the somatosensory-ear-auditory-cortex-region and the caudal parietal area. Aligning cytoarchitectonic borders with motor topography, sensory genital responses and corticocortical projections identified a candidate region for genital motor cortex. Most subcortical genital-cortex-projections were analog to other thalamic, tectal or pontine projections of somatosensory cortex. Genital-cortex-specific subcortical projections targeted amygdala and nucleus submedius and accumbens. Microstimulation-effects and projections support a sexual function of genital cortex and suggest that genital cortex is a major hub of sexual sensorimotor processing in rodents.

Persistent Genital Arousal Disorder: A Review of Its Conceptualizations, Potential Origins, Impact, and Treatment.

INTRODUCTION: Persistent genital arousal disorder (PGAD) is a condition characterized by symptoms of physiologic (typically genital) sexual arousal in the absence of perceived subjective sexual arousal. The physiologic arousal can last hours or days, or it can occur constantly, and it does not typically remit after orgasm(s). The symptoms are usually described as distressing, intrusive, and unwanted. AIM: To review the available literature on PGAD. METHODS: A literature review through April 2016 was undertaken using terms persistent genital arousal disorder, persistent sexual arousal syndrome, and restless genital syndrome. MAIN OUTCOME MEASURES: The main outcome is a review of the conceptualization of PGAD, its prevalence, proposed etiologies and treatments, and its impact on psychosocial and sexual functioning. RESULTS: Much of the research on the potential etiologies and treatments of PGAD is published in the form of case studies. Several etiologies of PGAD have been proposed; however, a cause or causes have not been confirmed. A range of treatments has been explored primarily in case studies, from electroconvulsive therapy to oral medication, with variable success rates. Psychologically based treatments have been suggested but have yet to be evaluated. Online surveys have found initial evidence supporting the negative impact of PGAD on mental health and sexual functioning; however, more research is needed in this area. CONCLUSION: Although PGAD was first conceptualized 15 years ago, it remains a very under-researched condition. Currently, little is known about its biopsychosocial correlates, etiologies, or successful treatments. Future research directions are identified.

In Situ Detection of Regulatory T Cells in Human Genital Herpes Simplex Virus Type 2 (HSV-2) Reactivation and Their Influence on Spontaneous HSV-2 Reactivation.

BACKGROUND: Herpes simplex virus type 2 (HSV-2) reactivation is accompanied by a sustained influx of CD4(+) and CD8(+) T cells that persist in genital tissue for extended periods. While CD4(+) T cells have long been recognized as being present in herpetic ulcerations, their role in subclinical reactivation and persistence is less well known, especially the role of CD4(+) regulatory T cells (Tregs). METHODS: We characterized the Treg (CD4(+)Foxp3(+)) population during human HSV-2 reactivation in situ in sequential genital skin biopsy specimens obtained from HSV-2-seropositive subjects at the time of lesion onset up to 8 weeks after healing. RESULTS: High numbers of Tregs infiltrated to the site of viral reactivation and persisted in proximity to conventional CD4(+) T cells (Tconvs) and CD8(+) T cells. Treg density peaked during the lesion stage of the reactivation. The number of Tregs from all time points (lesion, healed, 2 weeks after healing, 4 weeks after healing, and 8 weeks after healing) was significantly higher than in control biopsy specimens from unaffected skin. There was a direct correlation between HSV-2 titer and Treg density. CONCLUSIONS: The association of a high Treg to Tconv ratio with high viral shedding suggests that the balance between regulatory and effector T cells influences human HSV-2 disease.

Axotomy of tributaries of the pelvic and pudendal nerves induces changes in the neurochemistry of mouse dorsal root ganglion neurons and the spinal cord.

Using immunohistochemical techniques, we characterized changes in the expression of several neurochemical markers in lumbar 4-sacral 2 (L4-S2) dorsal root ganglion (DRG) neuron profiles (NPs) and the spinal cord of BALB/c mice after axotomy of the L6 and S1 spinal nerves, major tributaries of the pelvic (targeting pelvic visceral organs) and pudendal (targeting perineum and genitalia) nerves. Sham animals were included. Expression of cyclic AMP-dependent transcription factor 3 (ATF3), calcitonin gene-related peptide (CGRP), transient receptor potential cation channel subfamily V, member 1 (TRPV1), tyrosine hydroxylase (TH) and vesicular glutamate transporters (VGLUT) types 1 and -2 was analysed seven days after injury. L6-S1 axotomy induced dramatic de novo expression of ATF3 in many L6-S1 DRG NPs, and parallel significant downregulations in the percentage of CGRP-, TRPV1-, TH- and VGLUT2-immunoreactive (IR) DRG NPs, as compared to their expression in uninjured DRGs (contralateral L6-S1-AXO; sham mice); VGLUT1 expression remained unaltered. Sham L6-S1 DRGs only showed a small ipsilateral increase in ATF3-IR NPs (other markers were unchanged). L6-S1-AXO induced de novo expression of ATF3 in several lumbosacral spinal cord motoneurons and parasympathetic preganglionic neurons; in sham mice the effect was limited to a few motoneurons. Finally, a moderate decrease in CGRP- and TRPV1-like-immunoreactivities was observed in the ipsilateral superficial dorsal horn neuropil. In conclusion, injury of a mixed visceral/non-visceral nerve leads to considerable neurochemical alterations in DRGs matched, to some extent, in the spinal cord. Changes in these and potentially other nociception-related molecules could contribute to pain due to injury of nerves in the abdominopelvic cavity.

Do cutaneous nerves cross the midline?

Standard cutaneous innervation maps show strict midline demarcation. Although authors of these maps accept variability of peripheral nerve distribution or occasionally even the midline overlap of cutaneous nerves, this concept seems to be neglected by many other anatomists. To support the statement that such transmedian overlap exists, we performed an extensive literature search and found ample evidence for all regions (head/neck, thorax/abdomen, back, perineum, and genitalia) that peripheral nerves cross the midline or communicate across the midline. This concept has substantial clinical implications, most notably in anesthesia and perineural tumor spread. This article serves as a springboard for future anatomical, clinical, and experimental research.

Anatomical study of the iliohypogastric, ilioinguinal, and genitofemoral nerves using high-resolution ultrasound.

INTRODUCTION: In this study we aimed to determine whether high-resolution ultrasound (US) can identify the iliohypogastric (IH), ilioinguinal (II), and genitofemoral (GF) nerves and their relations. METHODS: This investigation, initially undertaken in cadavers, was followed by a high-resolution US study in 30 healthy adult volunteers (180 nerves) by 2 musculoskeletal radiologists on separate occasions, using 2 different approaches (proximal to distal and distal to proximal). A 0-3 scale was used to assess nerve visibility. Location and course of the IH, II, and GF nerves and their relations to adjacent anatomical structures were analyzed. RESULTS: Nerves and their terminal branches were better visualized with the distal-to-proximal approach (P < 0.05). Visualization of the terminal branches was possible in up to 60% of volunteers. CONCLUSIONS: High-resolution ultrasound (US) can identify the IH, II, and GF nerves at the level of the abdominal wall and the terminal branches in the majority of volunteers.

On the origin of grasshopper oviposition behavior: structural homology in pregenital and genital motor systems.

In female grasshoppers, oviposition is a highly specialized behavior involving a rhythm-generating neural circuit, the oviposition central pattern generator, unusual abdominal appendages, and dedicated muscles. This study of Schistocerca americana (Drury) grasshoppers was undertaken to determine whether the simpler pregenital abdominal segments, which do not contain ovipositor appendages, share common features with the genital segment, suggesting a roadmap for the genesis of oviposition behavior. Our study revealed that although 5 of the standard pregenital body wall muscles were missing in the female genital segment, homologous lateral nerves were, indeed, present and served 4 ovipositor muscles. Retrograde labeling of the corresponding pregenital nerve branches in male and female grasshoppers revealed motor neurons, dorsal unpaired median neurons, and common inhibitor neurons which appear to be structural homologues of those filled from ovipositor muscles. Some pregenital motor neurons displayed pronounced contralateral neurites; in contrast, some ovipositor motor neurons were exclusively ipsilateral. Strong evidence of structural homology was also obtained for pregenital and ovipositor skeletal muscles supplied by the identified neurons and of the pregenital and ovipositor skeletons. For example, transient embryonic segmental appendages were maintained in the female genital segments, giving rise to ovipositor valves, but were lost in pregenital abdominal segments. Significant proportional differences in sternal apodemes and plates were observed, which partially obscure the similarities between the pregenital and genital skeletons. Other changes in reorganization included genital muscles that displayed adult hypertrophy, 1 genital muscle that appeared to represent 2 fused pregenital muscles, and the insertion points of 2 ovipositor muscles that appeared to have been relocated. Together, the comparisons support the idea that the oviposition behavior of genital segments is built upon a homologous, segmentally iterated motor infrastructure located in the pregenital abdomen of male and female grasshoppers.

Rhythmic motor patterns accompanying ejaculation in spinal cord-transected male rats.

A spinal pattern generator controls the ejaculatory response. Activation of this spinal generator elicits rhythmic motor patterns of the striated musculature that surrounds the genital tract that contributes to the expulsion of seminal secretions. In the present study, we elicited ejaculation in spinal cord-transected male rats by mechanically stimulating the urethra and registered rhythmic motor patterns in the cremasteric, iliopsoas and pubococcygeus muscles. The rhythmic motor activity recorded in these muscles was compared with that elicited in the bulbospongiosus muscles; the results revealed similarities in the motor parameters among all the muscles. Data of this study, showing the occurrence of rhythmic motor behaviour in the cremasteric, iliopsoas and pubococcygeus muscles during ejaculation, suggest that these muscles might be under the control of the spinal generator for ejaculation.

Reports of intimate touch: erogenous zones and somatosensory cortical organization.

INTRODUCTION: Erogenous zones have paradoxical response properties, producing erotic feelings from body surfaces distant from the genitalia. Ramachandran has suggested an intriguing neuroscientific explanation for the distribution of erogenous zones, based on the arrangement of body parts (such as the adjacent positioning of the genitals and the feet) in primary somatosensory cortex (S1). The present study represents the first systematic survey of the magnitude of erotic sensations from various body parts, as well as the first empirical investigation of the S1 theory of erogenous zones, by analysis of whether evaluations of erogenous magnitude from adjacent S1 sites tend to correlate. METHODS: A sample of some 800 participants, primarily from the British Isles and Sub-Saharan Africa, completed a survey of 41 body parts, each rated for erogenous intensity. RESULTS: Ratings for the feet were surprisingly low. However, there were remarkable levels of correlation between ratings of intensity, regardless of the age, sexual orientation, nationality, race and, more surprisingly, the sex of our participant sample (R(2) values ranging between .90 and .98). Multiple regression and factor analysis investigated whether body parts nearby in S1 were significantly correlated. CONCLUSION: The S1 hypothesis appears to lack support, because of the low level of foot ratings, the lack of inter-correlation between ratings for nearby S1 sites, and the previous literature suggesting that cortical stimulation of S1 does not appear to be erotogenic. The consistency across demographic variables is open to multiple interpretations. However, it may be that individual experience or cultural differences (a starting point for some accounts of erogenous zone distribution) are not substantial determining variables. Thus, while S1 does not appear to be the likely site that would support Ramachandran's neural body map proposal, we suggest that the origins of erogenous distribution may derive from a map located elsewhere in the brain.

Acute effect of electrical stimulation of the dorsal genital nerve on rectal capacity in patients with spinal cord injury.

BACKGROUND: Constipation and fecal incontinence are considerable problems for most individuals with spinal cord injury (SCI). Neurogenic bowel symptoms are caused by several factors including abnormal rectal wall properties. Stimulation of the dorsal genital nerve (DGN) can inhibit bladder contractions and because of common innervation inhibitory effects are anticipated in the rectum too. Therefore, DNG could have a future role in the treatment of neurogenic fecal incontinence. AIM: To study the effect of acute DGN stimulation on the rectal cross sectional area (CSA) in SCI patients. METHODS: Seven patients with complete supraconal SCI (median age 50 years) were included. Stimulation was applied via plaster-electrodes using an amplitude of twice the genito-anal reflex threshold (pulse width: 200 µs; pulse rate: 20 Hz). A pressure controlled phasic (10, 20 and 30 cmH(2)O) rectal distension protocol was repeated four times with subjects randomized to stimulation during 1st and 3rd distension series or 2nd and 4th distension series. The rectal CSA and pressure were measured using impedance planimetry and manometry. RESULTS: All patients completed the investigation. Median stimulation amplitude was 51 mA (range 30-64). CSA was smaller during stimulation and differences reached statistical significance at distension pressures of 20 cmH(2)O (average decrease 9%; P = 0.02) and 30 cmH(2)O (average decrease 4%; P = 0.03) above resting rectal pressure. Accordingly, rectal pressure-CSA relation was significantly reduced during stimulation at 20 (P=0.03) and 30 cmH(2)O distension (P=0.02). CONCLUSION: DGN Stimulation in patients with supraconal SCI results in an acute decrease of rectal CSA and the rectal pressure-CSA relation.

A systematic analysis of Drosophila gustatory receptor gene expression in abdominal neurons which project to the central nervous system.

In Drosophila, the gustatory receptor (Gr) gene family contains 60 family members that encode 68 proteins through alternative splicing. Some gustatory receptors (Grs) are involved in the sensing of sugars, bitter substrates, CO(2), pheromones, and light. Here, we systematically examined the expression of all 68 Grs in abdominal neurons which project to the abdominal ganglion of the central nervous system using the GAL4/UAS system. Gr gene expression patterns have been successfully analyzed in previous studies by using the GAL4/UAS system to drive reporter gene expression. Interestingly, 21 Gr-GAL4 drivers showed abdominal ganglion projection, and 18 of these 21 Gr-GAL4 drivers labeled multidendritic neurons of the abdominal wall. 4 drivers also labeled neuronal processes innervating the reproductive organs. The peripheral expression of Gr-GAL4 drivers in abdominal multidendritic neurons or neurons innervating the reproductive organs suggests that these Grs have atypical sensory functions in these organs not limited to conventional taste sensing.

Somatic genital reflexes in rats with a nod to humans: anatomy, physiology, and the role of the social neuropeptides.

Somatic genital reflexes such as ejaculation and vaginocervical contractions are produced through the striated muscles associated with the genitalia. The coordination of these reflexes is surprisingly complex and involves a number of lumbosacral spinal and supraspinal systems. The rat model has been proven to be an excellent source of information regarding these mechanisms, and many parallels to research in humans can be drawn. An understanding of the spinal systems involving the lumbosacral spinal cord, both efferent and afferent, has been generated through decades of research. Spinal and supraspinal mechanisms of descending excitation, through a spinal ejaculation generator in the lumbar spinal cord and thalamus, and descending inhibition, through the ventrolateral medulla, have been identified and characterized both anatomically and physiologically. In addition, delineation of the neural circuits whereby ascending genitosensory information regarding the regulation of somatic genital reflexes is relayed supraspinally has also been the topic of recent investigation. Lastly, the importance of the "social neuropeptides" oxytocin and vasopressin in the regulation of somatic genital reflexes, and associated sociosexual behaviors, is emerging. This work not only has implications for understanding how nervous systems generate sexual behavior but also provides treatment targets for sexual dysfunction in people.

How generalized CNS arousal strengthens sexual arousal (and vice versa).

Heightened states of generalized CNS arousal are proposed here to facilitate sexual arousal in both males and females. Genetic, pharmacologic and biophysical mechanisms by which this happens are reviewed. Moreover, stimulation of the genital epithelia, as triggers of sex behavior, is hypothesized to lead to a greater generalized arousal in a manner that intensifies sexual motivation. Finally, launched from histochemical studies intended to characterize cells in the genital epithelium, a surprising idea is proposed that links density of innervation with the efficiency of wound healing and with the capacity of that epithelium to stimulate generalized CNS arousal. Thus, bidirectional arousal-related mechanisms that foster sexual behaviors are envisioned as follows: from specific to generalized (as with genital stimulation) and from generalized to specific.