REVIEWS: Pathways of Sexual Desire

Does yoga improve sexual function? A systematic review and meta-analysis of randomized clinical trials

BACKGROUND

Yoga practice can increase blood flow in the genital area, increase muscular strength, and improve body perception, which is related to sexual function. This study aimed to summarize the available evidence about the effects of yoga on sexual function in adults.

METHODS

Systematic searches of five databases were conducted from inception to April 28, with the last update on September 28, 2023. Randomized clinical trials (RCTs) that compared yoga with nonintervention control groups on sexual function in adults. Risk of bias and certainty of evidence were assessed by the Cochrane risk of bias tool 2, and the GRADE approach, respectively. Summary effect size measures were calculated using a random-effects model estimation and are reported as standardized mean differences and 95% confidence intervals. Reporting followed the PRISMA guidelines.

RESULTS

Ten RCTs that comprised 730 adults (range mean age, 26.64-68.2 years; 680 [93.2 %] women) were included. For the primary outcome, yoga intervention was associated with a significant small improvement in sexual function (-0.31; -0.47 to -0.15, p = 0.0002), with some concerns about risk of bias in nine RCTs (90%) and low-certainty evidence. Subgroup analyses revealed that yoga interventions performed by women (-0.36; -0.52 to -0.21, p < 0.00001), healthy individuals (-0.38; -0.59 to -0.16, p = 0.0006), or middle-aged individuals (-0.44; -0.63 to -0.25, p < 00001) significantly improved sexual function compared with control groups.

CONCLUSION

Yoga was associated with a small improvement in sexual function compared with nonintervention control groups in adults. However, high-quality, larger RCTs are required to draw more definitive conclusions.

Assessment and treatment of compulsive sexual behavior disorder: a sexual medicine perspective

INTRODUCTION

The addition of compulsive sexual behavior disorder (CSBD) into the ICD-11 chapter on mental, behavioral, or neurodevelopmental disorders has greatly stimulated research and controversy around compulsive sexual behavior, or what has been termed "hypersexual disorder," "sexual addiction," "porn addiction," "sexual compulsivity," and "out-of-control sexual behavior."

OBJECTIVES

To identify where concerns exist from the perspective of sexual medicine and what can be done to resolve them.

METHODS

A scientific review committee convened by the International Society for Sexual Medicine reviewed pertinent literature and discussed clinical research and experience related to CSBD diagnoses and misdiagnoses, pathologizing nonheteronormative sexual behavior, basic research on potential underlying causes of CSBD, its relationship to paraphilic disorder, and its potential sexual health consequences. The panel used a modified Delphi method to reach consensus on these issues.

RESULTS

CSBD was differentiated from other sexual activity on the basis of the ICD-11 diagnostic criteria, and issues regarding sexual medicine and sexual health were identified. Concerns were raised about self-labeling processes, attitudes hostile to sexual pleasure, pathologizing of nonheteronormative sexual behavior and high sexual desire, mixing of normative attitudes with clinical distress, and the belief that masturbation and pornography use represent "unhealthy" sexual behavior. A guide to CSBD case formulation and care/treatment recommendations was proposed.

CONCLUSIONS

Clinical sexologic and sexual medicine expertise for the diagnosis and treatment of CSBD in the psychiatric-psychotherapeutic context is imperative to differentiate and understand the determinants and impact of CSBD and related "out-of-control sexual behaviors" on mental and sexual well-being, to detect forensically relevant and nonrelevant forms, and to refine best practices in care and treatment. Evidence-based, sexual medicine-informed therapies should be offered to achieve a positive and respectful approach to sexuality and the possibility of having pleasurable and safe sexual experiences.

Addressing the unspoken: sexual dysfunction in men with systemic lupus erythematosus, a call to action for rheumatologists

INTRODUCTION

Sexual dysfunction (SD) is highly prevalent and multifactorial; nevertheless, recent research has shed light on a notable phenomenon: male patients with systemic lupus erythematosus (SLE) exhibit an elevated prevalence of sexual function disorders compared with the general population. Despite this recognition, the precise nature and extent of this association remain incompletely understood.

OBJECTIVES

This comprehensive review aims to clarify the link by providing an overview of the fundamental components of normal male sexual function, delving into the pathogenesis of male SD and exploring the primary factors predisposing male SLE patients to SD. Additionally, the review offers insights into potential screening, diagnostic, and treatment strategies based on the current body of literature.

METHODS

A meticulous search of relevant literature was conducted using the PubMed and Google Scholar databases.

RESULTS

Studies exploring the correlation between SLE and SD in both genders have revealed a nearly 2-fold increased risk of SD among individuals with SLE compared with healthy counterparts. Moreover, these studies suggest that male SLE patients may have a higher susceptibility to SD, with reported prevalence ranging from 12% to 68%, compared with 0% to 22% in healthy individuals. Male patients with SLE are influenced by a spectrum of pathological factors, including pharmacological, psychological, and disease-related determinants, which, through their intricate interplay, elevate the likelihood of developing SD.

CONCLUSION

Healthcare professionals must remain vigilant in understanding the intricacies of human sexuality and its dysfunction, particularly in males with SLE. The objective is to establish effective and potentially standardized methods for promptly diagnosing and optimally managing SD, recognizing its significant impact on the quality of life for males living with SLE. The pivotal role of rheumatologists in initiating discussions about sexual health, diagnosing SD, investigating causes, and implementing tailored strategies is underscored as crucial in addressing this multifaceted issue.

Acute ethanol disrupts conditioned inhibition in the male rat

RATIONALE

Alcohol can disrupt conditioned sexual inhibition (CSI) established by first-order conditioning in male rats. CSI can also be induced using second-order conditioning, during which male rats are trained to associate a neutral odor with a nonreceptive female. As a result, when given access to two receptive females (one scented and one unscented) during a copulatory preference test, they display CSI toward the scented female.

OBJECTIVE

The present study examined the effect of low-to-moderate doses of alcohol on CSI and brain activation following exposure to alcohol and the olfactory cue alone.

METHODS

Sexually-naïve Long-Evans rats received alternate conditioning sessions with unscented receptive or scented (almond extract) non-receptive females. Following the conditioning phase, males were injected with saline, alcohol 0.5 g/kg or 1 g/kg, 45 min before a copulatory test with two receptive females, with one bearing the olfactory cue. Fos activation was later assessed, following exposure to alcohol and the olfactory cue alone, in several brain regions involved in the expression and regulation of male sexual behavior.

RESULTS

While males in the saline group displayed sexual avoidance towards the scented female, those injected with alcohol before the copulatory test, regardless of the dose, copulated indiscriminately with both females. Subsequent exposure to alcohol and the olfactory cue alone induced different Fos expression between groups in several brain regions.

CONCLUSIONS

Low to moderate doses of alcohol disrupt conditioned sexual inhibition in male rats and induce a differential pattern of neural activation, particularly in regions involved in the expression and regulation of sexual behavior.

"One a Day Keeps the Prison Away": Understanding the Experiences of Individuals Convicted of Sexual Offences Receiving Anti-Androgens for the Treatment of Problematic Sexual Arousal

Problematic sexual arousal (PSA) is an umbrella term to describe a range of clinical presentations related to excessive sexual thinking (e.g., sexual preoccupation) and sexual behavior (e.g., hypersexuality). Although such concepts are known to affect sexual recidivism among individuals convicted of sexual offences, PSA is not routinely or directly targeted in offending behavior programs in England and Wales. However, in recent years, there have been moves to incorporate pharmacological interventions for addressing this among people with sexual offence histories. Although some work to understand the experiences of those taking SSRI medication for this purpose has emerged, little is known about the experiences of service users taking anti-androgen medication. In this study, we interviewed all individuals in prison taking anti-androgens for the treatment of problematic sexual arousal following convictions for sexual offences in England at the time of data collection (N = 10). Using a phenomenologically oriented thematic analysis, we established themes pertaining to "Differing needs: Motivations for treatment," "Medication as a risk management strategy," and how the medication helped the men in their pursuit of "Discovering a 'new me'." This work contributes important knowledge to inform the development of ethical and effective prescribing of anti-androgen medication with this population and offer recommendations for both future research and the development of clinical practice.

Sexual function of transgender assigned female at birth seeking gender affirming care: a narrative review

Sexual health is pivotal to the overall health and well-being of individuals. To date, transgender persons' sexual function results to be poorly investigated. Gender affirming medical and/or surgical treatments (GAMSTs) in transgender assigned female at birth (t-AFAB) can have an impact on overall quality of life and subsequently on sexual life. Before GAMSTs, literature shows a low sexual wellbeing of t-AFAB due to a complex interaction of organic and psychological factors. During gender affirming hormone therapy, testosterone treatments induce virilization that results in a better sexual satisfaction, in particular for sexual desire, arousal and orgasm. The majority of the available literature reports an increased sexual quality of life among t-AFAB after gender affirming surgery. Nevertheless, the different surgical techniques, the possible post-operative complications and sexual pain can negatively influence sexual function. Thus, this narrative review aims to summarize the available data about modifications on sexual health status in t-AFAB before and after GAMSTs. In transgender population, dealing with the evaluation of sexual life and satisfaction represents a relevant topic with a view to promote and sustain not only sexual wellbeing but especially general quality of life.

Effects of cabergoline and dimethylcabergoline on the sexual behavior of male rats

RATIONALE

Cabergoline (CAB) is an ergot derivative typically prescribed for the treatment of hyperprolactinemia. It suppresses the release of prolactin through agonist actions on dopamine (DA) D2 receptors; however, it possesses binding affinity for other DA and 5-HT receptors. Side effects that exacerbate valvular heart disease can occur with high doses.

OBJECTIVE

The present study examined the acute, subchronic, and chronic dose-response effects of CAB and a derivative dimethylcabergoline (DMC) which acts as an antagonist instead of agonist at 5-HT 2B receptors, on appetitive and consummatory sexual behaviors of male rats.

METHODS

CAB (0, 0.03, 0.15, or 0.3 mg/kg/ml) was administered daily to sexually experienced male rats (N = 10/dose) by oral gavage for a total of 68 days. Sexual behavior was tested every 4 days during this period for a total of 16 trials. On the 17th trial, rats were administered their dose of CAB, and 4 h after were overdosed with sodium pentobarbital, perfused intracardially, and their brains processed for Fos immunohistochemistry. DMC (0, 0.03, 0.15, 0.3 mg/kg/ml) was administered daily to sexually experienced male rats (N = 10/dose) by oral gavage for a total of 36 days. Sexual behavior was tested every 4 days for a total of 9 trials.

RESULTS

CAB increased anticipatory level changes, intromissions, and ejaculations significantly across all timepoints, with the medium and high doses being most potent. The medium and high doses also increased Fos protein significantly within the medial preoptic area, whereas in the nucleus accumbens shell, the low and medium doses decreased Fos protein but the high dose increased it significantly from control. Similar to CAB, the medium and high doses of DMC increased the number of ejaculations significantly. Rats in all drug dose groups appeared healthy for the duration of the experiments.

CONCLUSIONS

Both CAB and DMC facilitate ejaculations, and CAB further facilitates measures of anticipatory sexual motivation and intromissions. These data suggest that both could be used as treatments for sexual arousal disorders and ejaculation/orgasm disorders with little or no untoward side effects at low doses.

Sexual coordination in a whole-brain map of prairie vole pair bonding

Sexual bonds are central to the social lives of many species, including humans, and monogamous prairie voles have become the predominant model for investigating such attachments. We developed an automated whole-brain mapping pipeline to identify brain circuits underlying pair-bonding behavior. We identified bonding-related c-Fos induction in 68 brain regions clustered in seven major brain-wide neuronal circuits. These circuits include known regulators of bonding, such as the bed nucleus of the stria terminalis, paraventricular hypothalamus, ventral pallidum, and prefrontal cortex. They also include brain regions previously unknown to shape bonding, such as ventromedial hypothalamus, medial preoptic area, and the medial amygdala, but that play essential roles in bonding-relevant processes, such as sexual behavior, social reward, and territorial aggression. Contrary to some hypotheses, we found that circuits active during mating and bonding were largely sexually monomorphic. Moreover, c-Fos induction across regions was strikingly consistent between members of a pair, with activity best predicted by rates of ejaculation. A novel cluster of regions centered in the amygdala remained coordinated after bonds had formed, suggesting novel substrates for bond maintenance. Our tools and results provide an unprecedented resource for elucidating the networks that translate sexual experience into an enduring bond.

Aripiprazole and its adverse effects in the form of impulsive-compulsive behaviors: A systematic review of case reports

Aripiprazole is an efficacious treatment for both the positive and negative symptoms of schizophrenia and is also commonly used as a mood stabilizer. It is associated with better tolerability compared with other antipsychotics. However, there are reports of patients who experience problem gambling, hypersexuality, obsessive-compulsive symptoms, and other impulsive and/or compulsive behaviors as a result of aripiprazole administration and/or dosage increase. We aimed to do a systematic review of case reports published in this regard. After screening more than 6000 titles and abstracts in ten scientific search engines, we found 35 related records comprising 59 cases. The majority of cases (n = 42, 71.18%) were male, the mean age was 33.83 years (± 13.40), and the average daily dose of aripiprazole was 11.63 mg (± 6.94). The results of our review showed that the most frequently published impulsivity adverse effect of aripiprazole is gambling, followed by hypersexuality, obsessive-compulsive symptoms/disorder, problem eating, trichotillomania, problem shopping, and kleptomania. These symptoms were experienced both by patients who had previous problems in these areas and those who did not. In the majority of cases, the symptoms appeared within 30 days after aripiprazole administration started and ceased within 30 days of its discontinuation and/or dose decrease. Clinicians should be aware of impulsivity adverse effects, monitor them, and educate both patients and the family about them.

The Role of Dyadic Sexual Desire Similarity in Predicting Sexual Behaviors in Cohabitating Couples: An Ecological Momentary Assessment Study

Although researchers are increasingly paying attention to the dyadic nature of sexual desire and its relevance to sexual and relational outcomes, our understanding of how sexual desire operates on a couple level and how it may influence the occurrence of sexual activity in relationships remains limited. This study used ecological momentary assessments to explore to what extent similarity in levels of desire for sex with one's sexual partner, or dyadic sexual desire, was associated with sexual initiations, receptivity to one's partner's initiations, and partnered sexual activity, and how these associations were moderated by perceived partner support. Ninety-four cohabitating couples (M age = 26.30, SD = 7.60) provided six reports a day for 10 consecutive days. We used response surface analysis to examine the associations among both the degree and direction of (dis)similarity in partners' dyadic desire and each of the three outcome variables. Our results revealed that although partners tended to experience similar levels of desire on a moment-to-moment basis, similarity in desire levels was not associated with the three outcome variables. Rather, higher desire within couples predicted each partner's behavioral outcomes. At lower levels of perceived partner support, dyadic sexual desire was negatively associated with women's receptivity to sexual initiations by their partners, indicating high context-sensitivity of women's sexual responding. These findings offer new insights into the links between the similarity in partners' levels of dyadic desire and sexual behaviors in couples, suggesting the need for increased focus on maintaining desire and promoting perceived partner support in clinical practice.

Listening to your partner: serotonin increases male responsiveness to female vocal signals in mice

The context surrounding vocal communication can have a strong influence on how vocal signals are perceived. The serotonergic system is well-positioned for modulating the perception of communication signals according to context, because serotonergic neurons are responsive to social context, influence social behavior, and innervate auditory regions. Animals like lab mice can be excellent models for exploring how serotonin affects the primary neural systems involved in vocal perception, including within central auditory regions like the inferior colliculus (IC). Within the IC, serotonergic activity reflects not only the presence of a conspecific, but also the valence of a given social interaction. To assess whether serotonin can influence the perception of vocal signals in male mice, we manipulated serotonin systemically with an injection of its precursor 5-HTP, and locally in the IC with an infusion of fenfluramine, a serotonin reuptake blocker. Mice then participated in a behavioral assay in which males suppress their ultrasonic vocalizations (USVs) in response to the playback of female broadband vocalizations (BBVs), used in defensive aggression by females when interacting with males. Both 5-HTP and fenfluramine increased the suppression of USVs during BBV playback relative to controls. 5-HTP additionally decreased the baseline production of a specific type of USV and male investigation, but neither drug treatment strongly affected male digging or grooming. These findings show that serotonin modifies behavioral responses to vocal signals in mice, in part by acting in auditory brain regions, and suggest that mouse vocal behavior can serve as a useful model for exploring the mechanisms of context in human communication.

Acute dorsal genital nerve stimulation increases subjective arousal in women with and without spinal cord injury: a preliminary investigation

Introduction

Female sexual dysfunction (FSD) impacts an estimated 40% of women. Unfortunately, female sexual function is understudied, leading to limited treatment options for FSD. Neuromodulation has demonstrated some success in improving FSD symptoms. We developed a pilot study to investigate the short-term effect of electrical stimulation of the dorsal genital nerve and tibial nerve on sexual arousal in healthy women, women with FSD, and women with spinal cord injury (SCI) and FSD.

Methods

This study consists of a randomized crossover design in three groups: women with SCI, women with non-neurogenic FSD, and women without FSD or SCI. The primary outcome measure was change in vaginal pulse amplitude (VPA) from baseline. Secondary outcome measures were changes in subjective arousal, heart rate, and mean arterial pressure from baseline. Participants attended one or two study sessions where they received either transcutaneous dorsal genital nerve stimulation (DGNS) or tibial nerve stimulation (TNS). At each session, a vaginal photoplethysmography sensor was used to measure VPA. Participants also rated their level of subjective arousal and were asked to report any pelvic sensations.

Results

We found that subjective arousal increased significantly from before to after stimulation in DGNS study sessions across all women. TNS had no effect on subjective arousal. There were significant differences in VPA between baseline and stimulation, baseline and recovery, and stimulation and recovery periods among participants, but there were no trends across groups or stimulation type. Two participants with complete SCIs experienced genital sensations.

Discussion

This is the first study to measure sexual arousal in response to acute neuromodulation in women. This study demonstrates that acute DGNS, but not TNS, can increase subjective arousal, but the effect of stimulation on genital arousal is inconclusive. This study provides further support for DGNS as a treatment for female sexual dysfunction.

Does MDMA have treatment potential in sexual dysfunction? A systematic review of outcomes across the female and male sexual response cycles

INTRODUCTION

Sexual health, an integral component of overall well-being, is frequently compromised by common yet underdiagnosed sexual dysfunctions. Traditional interventions encompass pharmaceutical and psychological treatments. Unconventional therapies, like MDMA, offer hope for sexual dysfunction. This review delves into MDMA's effects on sexual responsiveness and its potential role in treating sexual dysfunction.

OBJECTIVES

The purpose of this review is to elucidate effects of MDMA on different domains of the female and male sexual response cycles.

METHODS

We conducted a systematic review on the effects of MDMA on each domain of the female and male sexual response cycles. PubMed, MEDLINE, and EMBASE were queried, and results were screened using PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Search terms utilized were "MDMA" or "ecstasy" in combination with "desire," "arousal," "lubrication," "orgasm," "pleasure," "libido," "erection," and "ejaculation." Inclusion criteria for this review were MDMA use by study subjects and sexual outcomes in at least 1 domain of the female and/or male sexual response cycles were described and measured. Randomized controlled trials, cohort studies (both prospective and retrospective), surveys, and literature reviews published between January 2000 and June 2022 were included. Case reports and studies that did not address conditions of interest were excluded from analysis. Duplicated search results were screened out. The remaining studies were then read in full text to ensure they met inclusion and exclusion criteria for analysis.

RESULTS

We identified 181 studies, of which 6 met criteria for assessment of the female sexual response cycle and 8 met criteria for assessment of the male sexual response cycle. Four of 6 studies reported increased sexual desire with MDMA use among women. Arousal and lubrication were improved with MDMA use in 3 of 4 studies, but they were not affected in 1 randomized control study. In men, 7 studies evaluated the effects of MDMA on desire and/or arousal, 5 studies measured impact on erection, 3 on orgasm, and 2 on ejaculation. Sixty percent of interview-based studies reported increased sexual desire in men, while 40% reported mixed or no effect. Two studies reported impairment of erection, 2 reported mixed effects, and 1 reported fear of erection impairment. In both men and women, all studies evaluating orgasm reported delay in achieving orgasm but increased intensity and pleasure if achieved. Primary outcome measures were variable and largely qualitative.

CONCLUSION

Our findings suggest that MDMA generally increases sexual desire and intensifies orgasm when achieved. While producing conflicting evidence on sexual arousal in both sexes, MDMA may impair erectile and ejaculatory function in men.

Pelvic organ prolapse after delivery: effects on sexual function, quality of life, and psychological health

BACKGROUND

Living with pelvic organ prolapse (POP) after delivery negatively impacted women's daily living and was detrimental to their psychological health.

AIM

The purpose of the present study was to explore the effects of POP after delivery on women's sexual function, quality of life (QoL), and psychological health within the first year following delivery.

METHODS

A cross-sectional study was conducted with 640 female participants at obstetric clinic in 2 hospitals in Shenzhen, China.

OUTCOMES

All women completed following questionnaires: short form of the Pelvic Organ Prolapse/Urinary Incontinence Sexual Questionnaire (PISQ-12) on sexual function, Pelvic Floor Distress Inventory-20 (PFDI-20) on well-being and QoL, Symptom Checklist-90-Revised (SCL-90-R) on psychological health, and International Consultation on Incontinence Questionnaire Short Form.

RESULTS

Women with symptomatic POP (N = 250) had higher mean scores (P < .05) than those without symptoms (N = 390) in PISQ-12, PFDI-20, and SCL-90-R domains. In the symptomatic POP group (N = 250), the sexually dysfunctional group (N = 137) had significantly higher mean scores (P < .001) than the sexually functional group (N = 113) in PISQ-12, PFDI-20, and SCL-90-R domains. Women with POP duration ≥6 months (N = 132) had significantly higher mean scores (P < .001) than women with POP duration <6 months (N = 118) in PISQ-12, PFDI-20, and SCL-90-R domains. The multiple linear regression model of PISQ-12 showed that constipation history, regular pelvic floor muscle training, parity, and symptomatic POP were independently correlated with the questionnaire score (P < .05).

CLINICAL IMPLICATIONS

The significantly pervasive nature of POP often leads to the neglect of a substantial percentage of sexual problems and related emotional suffering, emphasizing the critical importance of raising awareness about this issue among clinicians and the general public.

STRENGTHS AND LIMITATIONS

The current study brought attention to significant aspects of postpartum POP; the findings suggest issues concerning POP occurrences and their impacts on sexual function, QoL, and psychological health. Primary constraints are linked to the utilization of self-report assessments.

CONCLUSION

The current study reveals a robust correlation between POP in postpartum women and compromised sexual function, QoL, and psychological health.

Sexual coordination in a whole-brain map of prairie vole pair bonding

Sexual bonds are central to the social lives of many species, including humans, and monogamous prairie voles have become the predominant model for investigating such attachments. We developed an automated whole-brain mapping pipeline to identify brain circuits underlying pair-bonding behavior. We identified bonding-related c-Fos induction in 68 brain regions clustered in seven major brain-wide neuronal circuits. These circuits include known regulators of bonding, such as the bed nucleus of the stria terminalis, paraventricular hypothalamus, ventral pallidum, and prefrontal cortex. They also include brain regions previously unknown to shape bonding, such as ventromedial hypothalamus, medial preoptic area and the medial amygdala, but that play essential roles in bonding-relevant processes, such as sexual behavior, social reward and territorial aggression. Contrary to some hypotheses, we found that circuits active during mating and bonding were largely sexually monomorphic. Moreover, c-Fos induction across regions was strikingly consistent between members of a pair, with activity best predicted by rates of ejaculation. A novel cluster of regions centered in the amygdala remained coordinated after bonds had formed, suggesting novel substrates for bond maintenance. Our tools and results provide an unprecedented resource for elucidating the networks that translate sexual experience into an enduring bond.

Effects of autonomic nervous system disorders on male infertility

The male reproductive functions are largely regulated by the autonomic nervous system. Male sexual behavior and fertility primarily depend on the normal function of the higher neural centers related to the autonomic nervous system, the hypothalamic-pituitary-gonadal axis, the autonomic nervous components within the spinal cord and spinal nerves, and certain somatic nerves in the pelvic floor. In this review article, we will summarize the role of the autonomic nervous system in regulating male reproductive capabilities and fertility, its impact on male infertility under abnormal conditions, including the role of drug-induced autonomic nervous dysfunctions on male infertility. The main purpose of this article was to provide an overview of the effects of autonomic nervous dysfunction on male reproductive function and shed light on the potential therapeutic target for male infertility.

When the brain turns on with sexual desire: fMRI findings, issues, and future directions

INTRODUCTION

More than 2 decades of neuroimaging research has sought to uncover the neurologic basis of sexual desire. However, the lack of a clear conceptual distinction between sexual desire and sexual arousal or even a broadly accepted definition of sexual desire has led to confusion in the literature regarding brain areas uniquely associated with sexual desire.

OBJECTIVES

(1) To critically review the neuroimaging literature that seeks to identify brain areas and networks involved in sexual desire; (2) to identify and discuss those brain areas and potential networks that are most promising for providing insights to sexual desire; and (3) to offer recommendations for future studies.

METHODS

Existing meta-analyses were used as a starting point to identify relevant neuroimaging studies on sexual desire, arousal, and love. This base was then expanded via Google Scholar and forward citation tracking of already identified studies.

RESULTS

Brain areas that are commonly associated with sexual desire and arousal include the amygdala, hypothalamus, dorsal and ventral striatum, anterior cingulate, insula, and prefrontal and orbitofrontal cortex. However, because the same basic paradigm has been used to study sexual desire and arousal, unambiguous conclusions regarding areas uniquely involved in sexual desire cannot be drawn. Moreover, the lack of connectivity analyses and a failure to acknowledge negative BOLD (blood-oxygen level dependent) significantly limit conclusions on the neural basis of sexual desire.

CONCLUSION

Five recommendations are made. First, stimulus types (ie, erotic vs sexually explicit) should be selected by the meaningful theoretical conceptualization of the constructs of interest. Second, participants should be provided with definitions of sexual desire, mental sexual arousal, and perceived genital sexual arousal, so they can choose which terms best describe their experience. Third, event-related designs should be used with caution when investigating sexual desire. Fourth, time series analyses should be used to identify both positive and negative BOLD. Fifth, connectivity analyses should be performed to identify brain networks.

From distal to proximal to interactive: behavioral and brain synchrony during attraction, courtship, and sexual interaction-implications for clinical assessments of relationship style and quality

INTRODUCTION

Synchronous behaviors between individuals are nonverbal signs of closeness and common purpose. In the flow from initial attraction to intimate sexual interaction, attention and synchrony move from distal to proximal to interactive and are mediated by sensitized activation of neural systems for sexual motivation, arousal, and desire and those that recognize and mimic common facial and body movements between individuals. When reinforced by sexual pleasure and other relationship rewards, this results in the strengthening of attraction and bonding and the display of more common motor patterns. As relationships falter, nonverbal behaviors likely become asynchronous.

OBJECTIVES

To define behavioral, romantic, and sexual synchrony during phases of attraction and how their disruption can be observed and utilized by clinicians to assess individual relationship styles and quality.

METHODS

We review the literature on behavioral and attentional synchrony in humans and animals in an effort to understand experiential and innate mechanisms of synchrony and asynchrony and how they develop, as well as implications for attraction, relationship initiation, maintenance of romantic and sexual closeness, and relationship disintegration.

RESULTS

Evidence is presented that behavioral synchrony and the neural mechanisms that underlie it are vital to relationship formation and satisfaction.

CONCLUSION

Behavioral synchrony helps to create feelings of sexual and romantic synergy, cohesion, and arousal among individuals. Asynchrony is aversive and can spark feelings of discontent, aversion, and jealousy. Thus, observing patterns of nonverbal sexual and romantic synchrony between individuals offers insights into the potential quality of their relationships.

The Dual Control Model of Sexual Response: A Scoping Review, 2009-2022

The Dual Control Model proposes that sexual arousal and related processes are dependent on the balance between sexual excitation and sexual inhibition, and that individuals vary in their propensity for these processes. This scoping review provides an overview and discussion of the questionnaires used to measure the propensities for sexual excitation and inhibition, their translation and validation in other languages, and their application in empirical research on topics ranging from sexual desire and arousal, sexual (dys)function, sexual risk taking, asexuality, hypersexuality, and sexual aggression. A total of 152 papers, published between 2009 and 2022 and identified using online databases, were included in this review. The findings, consistent with those reviewed by Bancroft et al. (2009), suggest that sexual excitation is particularly relevant to sexual desire and responsivity and predictive of asexuality and hypersexuality. Sexual inhibition plays a role in sexual dysfunction. sexual risk taking, and sexual aggression, although often in interaction with sexual excitation. Suggestions for the further development of the model and for future studies are discussed.

The yin and yang of GSM and low sexual desire

Numerous surveys have documented that sexuality and/or sexual activity is important to women at all stages of adulthood, including postmenopause. Genitourinary syndrome of menopause (GSM) and hypoactive sexual desire disorder (HSDD) are common disorders in postmenopausal women and may co-occur. Both are often undiagnosed due to a lack of knowledge of the disorder, health-care professional discomfort in discussing sexual problems or a lack of routine screening. It is incumbent upon health-care professionals to identify and differentiate these conditions in women through a biopsychosocial assessment, and may require a focused physical examination. Numerous treatments, both non-pharmacologic and pharmacologic, are available to address GSM and HSDD.

What can challenging reproductive contexts tell us about the rat's maternal behavior?

Maternal behavior in mammals encompasses a complex repertoire of activities that ensure the survival of the offspring and shape their neural and behavioral development. The laboratory rat has been employed as a classic model for investigating maternal behavior, and recently with the use of advanced techniques, the knowledge of its neural basis has been expanded significantly. However, the standard laboratory testing conditions in which rats take care of a single litter impose constraints on the study of maternal flexibility. Interestingly, the reproductive characteristics of this species, including the existence of a fertile postpartum estrus, allow us to study maternal behavior in more complex and ethologically relevant contexts, even in laboratory settings. Here we review how maternal and sexual motivations interact during the postpartum estrus, shaping the behavioral response of females according to the presence of the pups and males. Next, we describe how impregnation during the postpartum estrus creates a new reproductive context in which mothers simultaneously care for two successive litters, adapting their responses to different behavioral and physiological demands of pups. These findings illustrate the behavioral adaptability of maternal rats to pups' needs and the presence of other reinforcers, as well as its dependence on the context. In our view, future perspectives in the field, by incorporating the use of cutting-edge techniques, should analyze maternal flexibility and its neural substrates in models that incorporate complex and challenging contexts. This approach would allow a more comprehensive understanding of brain circuits involved in the adaptive and flexible nature of parenting.

Levodopa-Induced Dyskinesias in Parkinson's Disease: An Overview on Pathophysiology, Clinical Manifestations, Therapy Management Strategies and Future Directions

Since its first introduction, levodopa has become the cornerstone for the treatment of Parkinson's disease and remains the leading therapeutic choice for motor control therapy so far. Unfortunately, the subsequent appearance of abnormal involuntary movements, known as dyskinesias, is a frequent drawback. Despite the deep knowledge of this complication, in terms of clinical phenomenology and the temporal relationship during a levodopa regimen, less is clear about the pathophysiological mechanisms underpinning it. As the disease progresses, specific oscillatory activities of both motor cortical and basal ganglia neurons and variation in levodopa metabolism, in terms of the dopamine receptor stimulation pattern and turnover rate, underlie dyskinesia onset. This review aims to provide a global overview on levodopa-induced dyskinesias, focusing on pathophysiology, clinical manifestations, therapy management strategies and future directions.

Measuring Sexual Motivation as a Trait Dimension: A multisample study of the Portuguese (European) Version of the Trait Sexual Motivation Questionnaire

The current study aimed at translating and validating the TSMQ into Portuguese-European (TSMQ-PT) and to investigate its psychometric properties. Three online studies were conducted with independent samples collected between September 2020 and March 2022. Study 1 tested the exploratory factorial structure (N = 325; 206 women); Study 2 explored the confirmatory factorial structure and construct validity (N = 450; 230 women); and Study 3 examined the temporal stability of the TSMQ-PT (N = 30; 15 women). Participants completed the TSMQ-PT for all three studies. In study 2, further completed the Sexual Compulsivity Scale, the Sexual Sensation Seeking Scale, and the Sexual Desire Inventory. Data revealed that the TSMQ-PT yielded a four-structure model, (i.e., Sexually Oriented, Comparison with Others, Seeking for Sexual Encounters, and Importance of Sex) comprising 13 items, with seven additional items for assessing existence and number of sexual partners, and frequency of sexual behaviors. The TSMQ-PT achieved good internal consistency levels (McDonald's omega ranged from .71 to .89) and construct validity, and temporal stability over 10-11 months (values ranged from .80 to .87) supporting the trait-dimension of sexual motivation. Current findings support a brief, valid, and reliable self-report instrument for assessing sexual motivation in the Portuguese context.

The endogenous cannabinoid system modulates male sexual behavior expression

The endocannabinoid system (ECS) plays a key neuromodulatory role in the brain. Main features of endocannabinoids (eCBs) are that they are produced on demand, in response to enhanced neuronal activity, act as retrograde messengers, and participate in the induction of brain plasticity processes. Sexual activity is a motivated behavior and therefore, the mesolimbic dopaminergic system (MSL) plays a central role in the control of its appetitive component (drive to engage in copulation). In turn, copulation activates mesolimbic dopamine neurons and repeated copulation produces the continuous activation of the MSL system. Sustained sexual activity leads to the achievement of sexual satiety, which main outcome is the transient transformation of sexually active male rats into sexually inhibited animals. Thus, 24 h after copulation to satiety, the sexually satiated males exhibit a decreased sexual motivation and do not respond to the presence of a sexually receptive female with sexual activity. Interestingly, blockade of cannabinoid receptor 1 (CB1R) during the copulation to satiety process, interferes with both the appearance of the long-lasting sexual inhibition and the decrease in sexual motivation in the sexually satiated males. This effect is reproduced when blocking CB1R at the ventral tegmental area evidencing the involvement of MSL eCBs in the induction of this sexual inhibitory state. Here we review the available evidence regarding the effects of cannabinoids, including exogenously administered eCBs, on male rodent sexual behavior of both sexually competent animals and rat sub populations spontaneously showing copulatory deficits, considered useful to model some human male sexual dysfunctions. We also include the effects of cannabis preparations on human male sexual activity. Finally, we review the role played by the ECS in the control of male sexual behavior expression with the aid of the sexual satiety phenomenon. Sexual satiety appears as a suitable model for the study of the relationship between eCB signaling, MSL synaptic plasticity and the modulation of male sexual motivation under physiological conditions that might be useful for the understanding of MSL functioning, eCB-mediated plasticity and their relationship with motivational processes.

Sexual Stimuli Cause Behavioral Disinhibition in Both Men and Women, but Even More So in Men

In our society men are considered more impulsive than women, especially in the violent and sexual domain. This correlation of sex and impulsivity might trace back to enhanced male impulsivity in general or a domain specific effect of emotions on impulsivity. The evidence for sex differences in the interaction of emotional or sexual stimuli and impulsivity has been relatively inconclusive so far. In this study, we investigated the effects of various emotional stimuli on responsivity in a Go/No-Go task. Participants had to respond quickly to a visual cue and withhold their response to another visual cue, while different emotional pictures were presented in the background, including sexual stimuli, non-sexual positive stimuli and negative stimuli. Both men (N = 37) and women (N = 38) made most commission errors in the sexual condition, indicating a disinhibiting effect in both genders. On top of this, men made even more commission errors than women, specifically in the sexual condition and not in other conditions. Men rated sexual stimuli as more positive, but did not differ from women in arousal ratings and pupil dilation. These findings may partly indicate increased impulsive behavior under sexual arousal in men, most likely driven by enhanced approach motivation due to more positive value but not higher arousal of sexual stimuli. The results are consistent with the theory of evolutionarily based concealment of sexual interest in women.

Melanocortin 4 receptor signaling in Sim1 neurons permits sexual receptivity in female mice

Introduction

Female sexual dysfunction affects approximately 40% of women in the United States, yet few therapeutic options exist for these patients. The melanocortin system is a new treatment target for hypoactive sexual desire disorder (HSDD), but the neuronal pathways involved are unclear.

Methods

In this study, the sexual behavior of female MC4R knockout mice lacking melanocortin 4 receptors (MC4Rs) was examined. The mice were then bred to express MC4Rs exclusively on Sim1 neurons (tbMC4RSim1 mice) or on oxytocin neurons (tbMC4ROxt mice) to examine the effect on sexual responsiveness.

Results

MC4R knockout mice were found to approach males less and have reduced receptivity to copulation, as indicated by a low lordosis quotient. These changes were independent of body weight. Lordosis behavior was normalized in tbMC4RSim1 mice and improved in tbMC4ROxt mice. In contrast, approach behavior was unchanged in tbMC4RSim1 mice but greatly increased in tbMC4ROxt animals. The changes were independent of melanocortin-driven metabolic effects.

Discussion

These results implicate MC4R signaling in Oxt neurons in appetitive behaviors and MC4R signaling in Sim1 neurons in female sexual receptivity, while suggesting melanocortin-driven sexual function does not rely on metabolic neural circuits.

Adverse childhood experiences and hormonal contraception: Interactive impact on sexual reward function

The current literature suggests that some women are uniquely vulnerable to negative effects of hormonal contraception (HC) on affective processes. However, little data exists as to which factors contribute to such vulnerability. The present study evaluated the impact of prepubertal adverse childhood experiences (ACEs) on reward processing in women taking HC (N = 541) compared to naturally cycling women (N = 488). Participants completed an online survey assessing current and past HC use and exposure to 10 different adverse childhood experiences (ACEs) before puberty (ACE Questionnaire), with participants categorized into groups of low (0-1) versus high (≥2) prepubertal ACE exposure. Participants then completed a reward task rating their expected and experienced valence for images that were either erotic, pleasant (non-erotic), or neutral. Significant interactions emerged between prepubertal ACE exposure and HC use on expected (p = 0.028) and experienced (p = 0.025) valence ratings of erotic images but not pleasant or neutral images. Importantly, follow-up analyses considering whether women experienced HC-induced decreases in sexual desire informed the significant interaction for expected valence ratings of erotic images. For current HC users, prepubertal ACEs interacted with HC-induced decreased sexual desire (p = 0.008), such that high ACE women reporting decreased sexual desire on HC showed substantially decreased ratings for anticipated erotic images compared to both high prepubertal ACE women without decreased sexual desire (p < 0.001) and low prepubertal ACE women also reporting decreased sexual desire (p = 0.010). The interaction was not significant in naturally cycling women reporting previous HC use, suggesting that current HC use could be impacting anticipatory reward processing of sexual stimuli among certain women (e.g., high prepubertal ACE women reporting HC-induced decreases in sexual desire). The study provides rationale for future randomized, controlled trials to account for prepubertal ACE exposure to promote contraceptive selection informed by behavioral evidence.

Reciprocal effects of single or repeated exposure to methylphenidate or sex in adult male rats

RATIONALE

Exposure to rewards can alter behavioral reactivity to them. For example, stimulants sensitize locomotor activation, whereas sexual experience sensitizes copulatory behaviors. Moreover, rewards can cross-sensitize one another. Although stimulants are known to cross-sensitize locomotor effects, the evidence for cross-sensitization between stimulants and sex is less clear.

OBJECTIVES

This study determined the effects of single and repeated pre-exposure to methylphenidate (MPH) or sex on one another in adult male rats.

METHODS

Cross-sensitization between MPH (5 mg/kg) and sex (30 min with sexually experienced female) was examined. Adult male rats were pre-exposed to 0, 1, or 10 trials of either sex or MPH before being exposed to the other reward. Locomotor chambers were used in MPH trials. Bilevel chambers were used in sexual trials, and sexual behaviors were video scored.

RESULTS

The amount of prior sexual experience differentially influenced the ceiling of MPH-dependent sensitization; in the last drug trial, locomotion was highest in males given 1 previous sexual trial compared with 0 or 10. Compared with MPH-naive males, pre-exposure to MPH (1 and 10 trials) reduced the number of ejaculations without impacting sexual performance (intromission/mount latency and frequency).

CONCLUSIONS

These findings indicate that the degree of pre-exposure to a reward can differentially affect reactivity to novel rewards. The results showed that previous findings of cross-sensitization between amphetamine and sex do not extend to MPH. However, exposure to MPH prior to sexual experience can increase the amount of sexual stimulation needed to achieve ejaculation.

The Effects of Radioligand Therapy on Quality of Life and Sexual Function in Patients with Neuroendocrine Neoplasms

Peptide receptor radionuclide therapy (PRRT), also called radioligand therapy, is an effective antitumoral treatment in patients with neuroendocrine neoplasm (NEN). It improves the patient's health-related quality of life (HRQoL), which is evaluated by self-assessment questionnaires. The aim of this narrative review was to report the current knowledge on the changes of HRQoL and sexual function in patients with NEN treated with PRRT. We conducted a literature search of the PubMed, Embase, and APA PsycInfo databases. We selected 15 studies (12 for HRQoL and three for sexual function). After treatment with PRRT, patients with NEN experienced a significant improvement in their global health status, disease-related worries, social and emotional functioning, and cancer-related symptoms such as fatigue and diarrhea. Other symptoms, such as nausea/vomiting, dyspnea, and constipation, as well as the economic impact, were unchanged by radioligand therapy. Data on sexual function were not equally promising; only a few studies investigated this issue by using appropriate questionnaires in patients treated with radioligand therapy. Therefore, additional studies are needed to draw a conclusion about the benefits from PRRT on sexual function.

Sexual experience increases oxytocin, but not vasopressin, receptor densities in the medial preoptic area, ventromedial hypothalamus, and central amygdala of male rats

Oxytocin (OT) and vasopressin (VP) are considered to be principal neurochemical substrates of bonding in monogamous species. We have reported previously that conditioning of a sexual partner preference in male rats resulted in conditioned activation of OT and VP neurons in hypothalamic paraventricular and supraoptc nuclei. Here we asked whether such conditioning would also alter OT or VP receptor densities. Sexually naïve male rats were assigned to one of three groups (n = 15/group). The Paired group received 9 copulatory training trials with sexually receptive females scented with a neutral almond odor. The Unpaired group received 9 copulatory training trials with unscented sexually receptive females. The Naïve group were not given sexual experience. Paired and Unpaired males were given a final test in an open field with two receptive females, one scented and the other unscented, to assess the development of conditioned ejaculatory preference (CEP), which was expressed significantly in the Paired group. Brains from rats in the three groups were then assessed for OT receptor (OTR) or VP1a receptor (VPR) densities within cortical, limbic and hypothalamic structures using autoradiography with selective 125I-labeled receptor ligands. Sexual experience alone increased OTR significantly in the medial preoptic area (mPOA), ventromedial hypothalamus (VMH), and central nucleus of the amygdala (CeA) in both Paired- and Unpaired-trained males compared to sexually Naïve males. No differences were found for experience on VPR densities in any region. These data add to a growing body of evidence that sexual experience alters brain function and processing of sex-related cues, and suggest that enhanced activation of OTRs in the mPOA, VMH, and CeA by conditioned OT release in those regions may underlie CEP in the male rat.

The World Federation of Societies of Biological Psychiatry guidelines on the assessment and pharmacological treatment of compulsive sexual behaviour disorder

OBJECTIVES

The current guidelines aim to evaluate the role of pharmacological agents in the treatment of patients with compulsive sexual behaviour disorder (CSBD). They are intended for use in clinical practice by clinicians who treat patients with CSBD.

METHODS

An extensive literature search was conducted using the English-language-literature indexed on PubMed and Google Scholar without time limit, supplemented by other sources, including published reviews.

RESULTS

Each treatment recommendation was evaluated with respect to the strength of evidence for its efficacy, safety, tolerability, and feasibility. Psychoeducation and psychotherapy are first-choice treatments and should always be conducted. The type of medication recommended depended mainly on the intensity of CSBD and comorbid sexual and psychiatric disorders. There are few randomised controlled trials. Although no medications carry formal indications for CSBD, selective-serotonin-reuptake-inhibitors and naltrexone currently constitute the most relevant pharmacological treatments for the treatment of CSBD. In cases of CSBD with comorbid paraphilic disorders, hormonal agents may be indicated, and one should refer to previously published guidelines on the treatment of adults with paraphilic disorders. Specific recommendations are also proposed in case of chemsex behaviour associated with CSBD.

CONCLUSIONS

An algorithm is proposed with different levels of treatment for different categories of patients with CSBD.

The nucleus accumbens dopamine increase, typically triggered by sexual stimuli in male rats, is no longer produced when animals are sexually inhibited due to sexual satiety

RATIONALE

Exposure of male rats to an inaccessible receptive female and copulation increases dopamine (DA) levels in the nucleus accumbens (NAcc). Males copulating to satiety become sexually inhibited and most of them do not display sexual activity when presented with a sexually receptive female 24 h later. This inhibitory state can be pharmacologically reversed. There are no studies exploring NAcc DA levels during this sexual inhibitory state.

OBJECTIVES

To characterize changes in NAcc DA and its metabolites' levels during sexual satiety development, during the well-established sexual inhibitory state 24 h later, and during its pharmacological reversal.

METHODS

Changes in NAcc DA and its metabolites were measured in sexually experienced male rats, using in vivo microdialysis, during copulation to satiety, when presented to a new sexually receptive female 24 h later, and during the pharmacological reversal of the sexual inhibition by anandamide.

RESULTS

NAcc DA levels remained increased during copulation to satiety. DA basal levels were significantly reduced 24 h after copulation to satiety, as compared to the initial basal levels. Presenting a receptive female behind a barrier 24 h after satiety did not induce the typical NAcc DA elevation in the sexually satiated males but there was a decrease that persisted when they got access to the female, with which they did not copulate. Anandamide injection slightly increased NAcc DA levels coinciding with sexual satiety reversal.

CONCLUSIONS

Reduced NAcc DA concentrations coincide with the inhibition of an instinctive, natural rewarding behavior suggesting that there might be a DA concentration threshold needed to be responsive to a rewarding stimulus.

Melanocortin 4 receptor agonism enhances sexual brain processing in women with hypoactive sexual desire disorder

BACKGROUND

Hypoactive sexual desire disorder (HSDD) is characterized by a persistent deficiency of sexual fantasies and desire for sexual activity, causing marked distress and interpersonal difficulty. It is the most prevalent female sexual health problem globally, affecting approximately 10% of women, but has limited treatment options. Melanocortin 4 receptor (MC4R) agonists have emerged as a promising therapy for women with HSDD, through unknown mechanisms. Studying the pathways involved is crucial for our understanding of normal and abnormal sexual behavior.

METHODS

Using psychometric, functional neuroimaging, and hormonal analyses, we conducted a randomized, double-blinded, placebo-controlled, crossover clinical study to assess the effects of MC4R agonism compared with placebo on sexual brain processing in 31 premenopausal heterosexual women with HSDD.

RESULTS

MC4R agonism significantly increased sexual desire for up to 24 hours after administration compared with placebo. During functional neuroimaging, MC4R agonism enhanced cerebellar and supplementary motor area activity and deactivated the secondary somatosensory cortex, specifically in response to visual erotic stimuli, compared with placebo. In addition, MC4R agonism enhanced functional connectivity between the amygdala and the insula during visual erotic stimuli compared with placebo.

CONCLUSION

These data suggest that MC4R agonism enhanced sexual brain processing by reducing self-consciousness, increasing sexual imagery, and sensitizing women with HSDD to erotic stimuli. These findings provide mechanistic insight into the action of MC4R agonism in sexual behavior and are relevant to the ongoing development of HSDD therapies and MC4R agonist development more widely.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04179734.

FUNDING

This is an investigator-sponsored study funded by AMAG Pharmaceuticals Inc., the Medical Research Council (MRC) (MR/T006242/1), and the National Institute for Health Research (NIHR) (CS-2018-18-ST2-002 and RP-2014-05-001).

Orgasm and Related Disorders Depend on Neural Inhibition Combined With Neural Excitation

INTRODUCTION

Prevalent models of sexual desire, arousal and orgasm postulate that they result from an excitatory process, whereas disorders of sexual desire, arousal and orgasm result from an inhibitory process based on psychosocial, pharmacological, medical, and other factors. But neuronal excitation and active neuronal inhibition normally interact at variable intensities, concurrently and continuously. We propose herein that in conjunction with neuronal excitation, neuronal inhibition enables the generation of the intense, non-aversive pleasure of orgasm. When this interaction breaks down, pathology can result, as in disorders of sexual desire, arousal, and orgasm, and in anhedonia and pain. For perspective, we review some fundamental behavioral and (neuro-) physiological functions of neuronal excitation and inhibition in normal and pathological processes.

OBJECTIVES

To review evidence that the variable balance between neuronal excitation and active neuronal inhibition at different intensities can account for orgasm and its disorders.

METHODS

We selected studies from searches on PubMed, Google Scholar, Dialnet, and SciELO for terms including orgasm, neuronal development, Wallerian degeneration, prenatal stress, parental behavior, sensorimotor, neuronal excitation, neuronal inhibition, sensory deprivation, anhedonia, orgasmic disorder, hypoactive sexual desire disorder, persistent genital arousal disorder, sexual pain.

RESULTS

We provide evidence that the intensity of neuronal inhibition dynamically covaries concurrently with the intensity of neuronal excitation. Differences in these relative intensities can facilitate the understanding of orgasm and disorders of orgasm.

CONCLUSION

Neuronal excitation and neuronal inhibition are normal, continuously active processes of the nervous system that are necessary for survival of neurons and the organism. The ability of genital sensory stimulation to induce concurrent neuronal inhibition enables the stimulation to attain the pleasurable, non-aversive, high intensity of excitation characteristic of orgasm. Excessive or deficient levels of neuronal inhibition relative to neuronal excitation may account for disorders of sexual desire, arousal and orgasm.

Paced Mating Behaviour Is Influenced by Duration of Female Post-Ejaculatory Interval

BACKGROUND

Laboratory paradigms that enable the female rat to control the frequency and temporal distribution of sexual stimulation are well-suited to gaining knowledge about female sexual function; however, the variety of procedures used influence the specific behaviors exhibited by female rats and bring uncertainty into the conclusions that can be drawn.

AIM

In this study, we evaluated the effects of test parameters on the display of paced mating behavior in female rats to develop better preclinical models for exploring female sexual health.

METHODS

Sexually experienced, estradiol- and progesterone-primed female rats were tested under paced mating conditions to determine whether sexual behavior differed as a function of number of male partners (1 or 3; Experiment 1), the time span between receipt of an ejaculation and the next intromission (ie, the post-ejaculatory interval or PEI; Experiment 2), or the duration of ejaculations (Experiment 3).

OUTCOMES

Contact-return latency, exit latency, and withdrawal duration after mounts, intromissions, and ejaculations.

RESULTS

The shorter withdrawal latency after intromission and longer return latency after ejaculation observed in 30-minute paced mating tests is best attributed to the female's PEI. The duration of the PEI is a specific factor that affects the display of paced mating behavior.

CLINICAL TRANSLATION

Understanding of neurobiological mechanisms and sensory factors influencing sexual behavior learned from these models can be applied to studies of human female sexual health.

STRENGTHS & LIMITATIONS

Sexual motivation is indicated by analogous behaviors and supported by evolutionarily conserved systems in women and rats, meaning that animal models can be used to identify neurobiological mechanisms subserving these behaviors. Nonetheless, data related specifically to physiological effects of different mating paradigms are needed in future research.

CONCLUSION

Procedures that mimic naturalistic settings, and thus enable female sexual motivation to drive behavior, are apt for studies aimed at understanding mechanisms supporting female sexual function whereas artificially lengthening the interval between an ejaculation and subsequent intromission may provide a model to study female sexual dysfunction.

Who feels affected by "out of control" sexual behavior? Prevalence and correlates of indicators for ICD-11 Compulsive Sexual Behavior Disorder in the German Health and Sexuality Survey (GeSiD)

BACKGROUND AND AIMS

The purpose of this study was to examine the prevalence and correlates of indicators consistent with Compulsive Sexual Behavior Disorder (CSBD)-defined and operationalized according to the ICD-11 guidelines-in a large (n = 4,633; 50.5% male; 49,5% female) probability-based German national sample.

METHODS

Participants were asked if they had ever experienced "intense and recurring sexual impulses or sexual urges that I had difficulty controlling and resulted in sexual behavior" over a period of several months. Those who reported this experience were queried about the associated distress.

RESULTS

Overall, 4.9% of men [95% CI = 3.9-6.1] and 3.0% of women [95% CI = 2.3-3.9] reported experiences consistent with ICD-11 diagnostic requirements for lifetime diagnosis. In the 12 months preceding the study, 3.2% of men [95% CI = 2.4-4.2] and 1.8% of women [95% CI = 1.2-2.5] reported experiences consistent with CSBD requirements. Compared to controls and participants who reported elements of compulsive sexuality but without accompanying distress, strict religious upbringing was most prevalent in the CSBD group. The CSBD group was more likely to view sexual practices like men having sex with men as unacceptable and to report the belief that pornography has negative impacts on their sex life and life in general. Compared to the other two groups, the CSBD group was significantly more likely to have received psychiatric treatment for depression or another mental health problem during the past 12 months.

DISCUSSION AND CONCLUSIONS

The current study provides novel and important insights into the prevalence and characteristics of CSBD in the general population.

Behavioral, Neural, and Molecular Mechanisms of Conditioned Mate Preference: The Role of Opioids and First Experiences of Sexual Reward

Although mechanisms of mate preference are thought to be relatively hard-wired, experience with appetitive and consummatory sexual reward has been shown to condition preferences for partner related cues and even objects that predict sexual reward. Here, we reviewed evidence from laboratory species and humans on sexually conditioned place, partner, and ejaculatory preferences in males and females, as well as the neurochemical, molecular, and epigenetic mechanisms putatively responsible. From a comprehensive review of the available data, we concluded that opioid transmission at μ opioid receptors forms the basis of sexual pleasure and reward, which then sensitizes dopamine, oxytocin, and vasopressin systems responsible for attention, arousal, and bonding, leading to cortical activation that creates awareness of attraction and desire. First experiences with sexual reward states follow a pattern of sexual imprinting, during which partner- and/or object-related cues become crystallized by conditioning into idiosyncratic “types” that are found sexually attractive and arousing. These mechanisms tie reward and reproduction together, blending proximate and ultimate causality in the maintenance of variability within a species.

Androgens and male sexual function

Sexual symptoms are the most specific determinants of low testosterone (T) observed during adulthood. In this narrative review, we summarize the most important evidence supporting the positive relationships between endogenous T levels and sexual activity in the adult male, by using preclinical and clinical observations. In addition, we also report an update of our previous meta-analysis evaluating the effects of T treatment (TRT) on sexual functioning in subjects with T deficiency. Available data indicate that TRT of symptomatic hypogonadal men can improve several aspects of sexual life, including erection. However, the effect is rather modest and lower in subjects with associated metabolic conditions. The specific observed effects are similar to those derived from lifestyle intervention. Since TRT might result in body composition improvement, it is reasonable to suppose that an initial treatment with T can improve the willingness of hypogonadal subjects to perform physical exercise and to adhere to a healthier behavior. Similar data were derived from animal models. However, it should be important to recognize that lifestyle modifications should be the first step to promote weigh reduction. TRT can be combined with lifestyle interventions only in symptomatic hypogonadal subjects especially in the presence of comorbid metabolic conditions.

Sex differences in carcinoid syndrome: A gap to be closed

The incidence of neuroendocrine neoplasms and related carcinoid syndrome (CS) has markedly increased over the last decades and women seem to be more at risk than men for developing CS. Nevertheless, very few studies have investigated sex differences in clinical presentation and outcomes of CS. However, as per other tumours, sex might be relevant in influencing tumour localization, delay in diagnosis, clinical outcomes, prognosis and overall survival in CS. The present review was aimed at evaluating sex differences in CS, as they emerge from an extensive search of the recent literature. It emerged that CS occurs more frequently in female than in male patients with NENs and women seem to have a better prognosis and a slight advantage in overall survival and response to therapy. Moreover, the disease likely impacts differently the quality of life of men and women, with different psychological and social consequences. Nevertheless, sex differences, even if partially known, are deeply underestimated in clinical practice and data from clinical trials are lacking. There is urgent need to increase our understanding of the sex-related differences of CS, in order to define tailored strategies of management of the disease, improving both the quality of life and the prognosis of affected patients.

The neurobiology of bremelanotide for the treatment of hypoactive sexual desire disorder in premenopausal women

Hypoactive sexual desire disorder (HSDD) is a common female sexual dysfunction and is estimated to affect approximately 10% of women in the United States. It has been suggested that HSDD is associated with an imbalance of hormone and neurotransmitter levels in the brain, resulting in decreased excitation, increased inhibition, or a combination of both. Evidence suggests neurotransmitters, including dopamine (DA), norepinephrine, and serotonin, as well as hormones such as estradiol and testosterone, contribute to female sexual desire and response. Current treatments for HSDD include psychotherapy, and two US Food and Drug Administration-approved medications for premenopausal women: flibanserin, a serotonin mixed agonist and antagonist, and bremelanotide, a melanocortin receptor (MCR) agonist. Melanocortins are endogenous neuropeptides associated with the excitatory pathway of the female sexual response system. MCRs are found throughout the body, including the brain. Bremelanotide is an MCR agonist that nonselectively activates several of the receptor subtypes, of which subtype 4 (MC4R) is the most relevant at therapeutic doses. MC4R is predominantly expressed in the medial preoptic area (mPOA) of the hypothalamus in the brain, and is important for female sexual function. Animal studies suggest that bremelanotide may affect female sexual desire by activating presynaptic MC4Rs on neurons in the mPOA of the hypothalamus, leading to increased release of DA, an excitatory neurotransmitter that increases sexual desire. This review presents what is known about the mechanism of action of bremelanotide in the context of treating HSDD.

Sacubitril/Valsartan Improves Sexual Function and Fibrosis of the Clitoral and Vaginal Tissues in Female Spontaneously Hypertensive Rats

ABSTRACT

Female sexual dysfunction is common in hypertension. The effects of sacubitril/valsartan (SAC/VAL) as a potential therapy for hypertension and heart failure have not been studied in relation to sexual function and genital fibrosis in female spontaneously hypertensive rats (SHRs). Thirty female SHRs were administered VAL, SAC/VAL, or saline. Ten normotensive female Wistar-Kyoto (WKY) rats were included in the control group. We assessed estrous cyclicity and sexual behavior in the female rats. In addition, the morphology of clitoral and vaginal tissues was evaluated by histological analyses. Western blotting and enzyme-linked immunosorbent assays were used to assess the levels of fibrotic markers in vaginal and clitoral tissues. Furthermore, the protein levels of phosphatase and tensin homolog deleted from chromosome 10 (PTEN), phosphoinositide-3-kinase (PI3K), and AKT expression were measured by Western blotting. SAC/VAL treatment improved hypertension-induced sexual dysfunction, exhibited as a prolonged estrus phase, increased receptivity and proceptive events, and decreased aggressive events, compared with those of VAL treatment and control SHRs without treatments. In addition, SAC/VAL-treated SHRs had lower levels of fibrotic markers, estradiol, and estrogen receptor α/β than the levels of VAL-treated SHRs or SHRs without treatment. Moreover, SAC/VAL decreased p-PTEN expression and increased p-PI3K and p-AKT expression at the protein level compared with those in VAL treatment alone. VAL and SAC/VAL treatments have significantly increased sexual receptivity and proceptivity, decreased aggressiveness, and improved the fibrosis of vaginal and clitoral tissues in female SHRs. However, SAC/VAL treatment shows more effective results compared with VAL treatment, which may be related to the PTEN/PI3K/AKT pathway.

Adolescence and Postpartum: Two Life Periods to Deepen Our Understanding of the Complexity of Female Rat Sexual Behavior

The sexual behavior of the female rat has been extensively studied and used as a model for human female sexuality. The development of models that focus on sexual interaction from the female’s perspective has demonstrated the complexity of this behavior, in which motivational and affective aspects have great relevance. This review describes, from a historical perspective, some of the studies that have shed light on this complexity and presents the potential of two periods in the female’s life to expand our understanding of sexual behavior: adolescence and postpartum estrus. Cycling adolescent female rats can express sexual behavior even though some of the underlying circuitry is still developing. Therefore, this is an ideal time for studying the ontogeny of sexual behavior, the interaction of sexual and social motivations, and the neuroendocrine changes that lead to adult behavior. Female rats also show a fertile estrus a few hours after parturition. During this period, rats are simultaneously sexually and maternally motivated, making postpartum estrus an excellent model for exploring the interaction of these two social motivations. What we know so far about female sexual behavior in these unique periods of life reaffirms its richness and shows that much remains to be known.

Pharmacological Treatment for Pedophilic Disorder and Compulsive Sexual Behavior Disorder: A Review

Guidelines for the pharmacological treatment of paraphilic disorders have historically been based on data from forensic settings and on risk levels for sexual crime. However, emerging treatment options are being evaluated for individuals experiencing distress because of their sexual urges and preferences, targeting both paraphilic disorders such as pedophilic disorder (PeD) and the new diagnosis of compulsive sexual behavior disorder (CSBD) included in the International Classification of Diseases, 11th Revision (ICD-11). As in other mental disorders, this may enable individualized pharmacological treatment plans, taking into account components of sexuality (e.g. high libido, compulsivity, anxiety-driven/sex as coping), medical and psychiatric comorbidity, adverse effects and patient preferences. In order to expand on previous reviews, we conducted a literature search focusing on randomized controlled trials of pharmacological treatment for persons likely to have PeD or CSBD. Our search was not restricted to studies involving forensic or criminal samples. Twelve studies conducted between 1974 and 2021 were identified regardless of setting (outpatient or inpatient), with only one study conducted during the last decade. Of a total of 213 participants included in these studies, 122 (57%) were likely to have PeD, 34 (16%) were likely to have a CSBD, and the remainder had unspecified paraphilias (40, 21%) or sexual offense (17, 8%) as the treatment indication. The diagnostic procedure for PeD and/or CSBD, as well as comorbid psychiatric symptoms, has been described in seven studies. The studies provide some empirical evidence that testosterone-lowering drugs reduce sexual activity for patients with PeD or CSBD, but the body of evidence is meager. There is a need for studies using larger samples, specific criteria for inclusion, longer follow-up periods, and standardized outcome measures with adherence to international reporting guidelines.

The Neurobiology of Behavior and Its Applicability for Animal Welfare: A Review

Simple Summary

Animal welfare is the result of physical and psychological well-being and is expected to occur if animals are free: (1) from hunger, thirst and malnutrition, (2) from discomfort, (3) from pain, (4) to express normal behavior, and (5) from fear and distress. Nevertheless, well-being is not a constant state but rather the result of certain brain dynamics underlying innate motivated behaviors and learned responses. Thus, by understanding the foundations of the neurobiology of behavior we fathom how emotions and well-being occur in the brain. Herein, we discuss the potential applicability of this approach for animal welfare. First, we provide a general view of the basic responses coordinated by the central nervous system from the processing of internal and external stimuli. Then, we discuss how those stimuli mediate activity in seven neurobiological systems that evoke innate emotional and behavioral responses that directly influence well-being and biological fitness. Finally, we discuss the basic mechanisms of learning and how it affects motivated responses and welfare.

Abstract

Understanding the foundations of the neurobiology of behavior and well-being can help us better achieve animal welfare. Behavior is the expression of several physiological, endocrine, motor and emotional responses that are coordinated by the central nervous system from the processing of internal and external stimuli. In mammals, seven basic emotional systems have been described that when activated by the right stimuli evoke positive or negative innate responses that evolved to facilitate biological fitness. This review describes the process of how those neurobiological systems can directly influence animal welfare. We also describe examples of the interaction between primary (innate) and secondary (learned) processes that influence behavior.

Are Endogenous Androgens Linked to Female Sexual Function? A Systemic Review and Meta-Analysis

BACKGROUND

The benefits of treatment with testosterone (T) in women with loss of desire suggest that low androgens may distinguish women with sexual dysfunction (SD) from others; however, evidence on this point is lacking.

AIM

To answer the question: is there an association between endogenous levels of androgens and sexual function in women?

METHODS

An extensive search was performed in MEDLINE, Embase and PsycInfo. Four separate meta-analyses were conducted for total T, free T, Free Androgen Index (FAI), and Dehydroepiandrosterone sulphate (DHEAS). Cohort, cross-sectional, and prospective studies were included.

OUTCOMES

The main outcome was the association between endogenous androgens and sexual desire. Global sexual function was considered as a secondary outcome. The effect measure was expressed as standardized mean difference (SMD).

RESULTS

The meta-analysis on total T included 34 studies involving 3,268 women, mean age 36.5 years. In 11 studies, a significant association was found between sexual desire, measured by validated psychometric instruments, and total T (SMD = 0.59 [0.29;0.88], P < 0.0001), with a moderate effect. The association with global sexual function (n = 12 studies) was also significant (SMD = 0.44 [0.21;0.67], P <0.0001). Overall, total T was associated with a better sexual function (SMD = 0.55 [0.28;0.82)], P < 0.0001), with similar results obtained when poor quality studies were removed. Age showed a negative relationship with the overall outcome. No differences were found when stratifying the studies according to menopausal status, type of menopause, age at menopause, use of hormonal replacement therapy, relationship status, method for T measurement, phase of the menstrual cycle or use of hormonal contraception. The meta-analysis of T derivatives (free T and FAI) also showed a significant, moderate association with sexual desire. In contrast, DHEAS seems not to exert any significant influence on desire, whilst showing a positive association with global sexual function.

CLINICAL IMPLICATIONS

Endogenous androgens show a moderate association with a better sexual function in women; however, the role of psychological, relational and other hormonal factors should not be overlooked.

STRENGTHS & LIMITATIONS

This represents the first attempt at meta-analyzing data available on the topic. A significant publication bias was found for total T.

CONCLUSION

There appears to be a moderate association between total T and sexual desire/global sexual function, which is confirmed, although weak, in studies employing liquid chromatography-mass spectrometry (LC-MS). Similar results on desire were obtained for free T and FAI. DHEAS only showed a positive association with global sexual function. More research is needed. Maseroli E and Vignozzi L. Are Endogenous Androgens Linked to Female Sexual Function? A Systemic Review and Meta-Analysis. J Sex Med 2022;19:553-568.