Male Sexual Behavior Research Articles

Past, Present, and Future of LGBTIQ Tourism Literature: A Systematic Literature Review

ABSTRACT This study conducts a systematic review of the current scientific research framework on LGBTIQ tourism and suggests new directions for its evolution. Through bibliometric analysis, content analysis, and systematic quantitative literature review, 146 articles from WoS and Scopus databases (1993–2023) were examined. Five research areas were identified: gay male sexual behaviors on holidays, discriminatory activities and attitudes, LGBT tourists’ identities, LGBTQIA events, and LGBTQ spaces. Existing literature mainly focuses on demand dynamics, specifically on gay tourists, their profiles, motivations, and experiences of discrimination. The article proposes future research directions to broaden and deepen the field of LGBTIQ tourism studies.

Diet acts on sexual behavior development in a male moth.

In many animals, drastic changes are observed during sexual maturation characterized by the reproductive system development concomitantly to the sexual behavior ontogenesis. These modifications are under the control of internal and external factors such as food. Sexual maturation requires considerable energetic investment, and diet has been shown to affect reproductive activities in many taxonomic groups, especially in insects and vertebrates. By contrast, diet effects on sexual behavior development remain largely unexplored. To elucidate this aspect, we used the male moth Agrotis ipsilon which undergoes sexual maturation occurring between the third and the fifth day postemergence. During this period, males are sensitive to female sex pheromones and a stereotypical sexual behavior characterized by female-oriented flight takes place. In our study, we compared (1) sex pheromone detection by electroantennography recordings and (2) behavioral response in wind tunnel assays between males fed with different diets found in nature. Compared to standard sucrose diet, males fed with sucrose, fructose, and glucose supplemented with sodium (a mineral element necessary for the locomotor activity in several moths) did not respond better to female sex pheromones but clearly exhibited an earlier behavioral response. Thus, such a diet accelerates the development of sex pheromone-mediated oriented flight, probably by facilitating the central processing of sex pheromone information in male A. ipsilon moths. Our results provide new information on the influence of nutritional intake on the ontogenesis of male sexual behavior in animals.

7089 The Effects of Asprosin on Reproductive Parameters in the Rats

Abstract Disclosure: H. Kelestimur: None. Z. Oz: None. M. Ozdede: None. &. Serhatlioglu: None. E. Kacar: None. B. Yilmaz: None. Purpose: Asprosin, a novel glucogenic adipokine produced by the fibrillin 1 (FBN1) gene, is integral to the body's energy regulation processes. Generated and released by white adipose tissue during fasting, asprosin affects the hypothalamic-pituitary-gonadal (HPG) axis, impacting reproduction. While its effects on metabolic parameters are well established, the understanding of its impact on reproductive health and functionality is still emerging. This study investigates the effects of exogenous asprosin administration on the reproductive capabilities of male and female rats. Materials and Methods: Forty-eight Sprague-Dawley rats, 21 days old and weighing 35±2 grams, were divided into control and asprosin-treated groups (n = 12 per group, for both genders). This approach allowed direct comparison between treated and untreated groups. From postnatal day 21, treatment groups received daily intraperitoneal injections of asprosin (500 ng/kg) for ten weeks (male) and eight weeks (female), while control groups received only saline (1 ml/kg). The study examined various reproductive parameters, including those related to pubertal maturation and sexual behavior, and conducted hormonal analyses on blood samples collected at the experiment's conclusion. Results: Asprosin administration did not alter puberty onset or weight in either gender. However, asprosin-treated rats showed significantly earlier sperm formation in males and earlier estrus in females compared to controls. In male sexual behavior, asprosin reduced intromission latency and increased ejaculation frequency. While interaction with females remained unchanged, asprosin notably increased time near males and male preference ratio. The rate of male investigation preference and the activity index (frequency of passing through the test device's center) also significantly increased in the asprosin-treated group. Conclusion: These findings suggest that asprosin may stimulate the reproductive system in both male and female rats. They highlight the potential role of asprosin in reproductive biology and underscore the need for further research to fully understand the mechanisms by which asprosin influences reproduction. Such studies could significantly advance our knowledge in endocrine regulation. Acknowledgement: This study was supported by TUBITAK (Project No: 220S744). Presentation: 6/1/2024

Rodent reproductive behavior among males and females after exposure to endocrine-disrupting chemicals.

Sexual reproduction-from both physiological and behavioral perspectives-is dependent upon appropriate connections between a diverse, hormone-modulated network of neural regions. Importantly, these substrates are regulated by hormones across the lifespan from early development to adulthood, making them targets of endocrine-disrupting chemicals (EDCs). Rodents, such as mice and rats, are invaluable to the characterization of EDCs because of their sex-specific, stereotyped appetitive and consummatory reproductive behaviors. Phthalates, bisphenol A (BPA), and EDC mixtures pose a salient risk to the health of humans, wildlife, and livestock because these synthetic compounds are ubiquitous due to their widespread use in mass production of consumer and industrial goods. This review outlines how the hypothalamic-pituitary-gonadal axis regulates male and female sexual behaviors, and how phthalates and BPA can perturb appetitive and consummatory behaviors and impact neural substrates that modulate reproductive behavior. We will then discuss how to progress toward a clearer understanding of the reproductive and neurobiological changes that occur due to EDC exposure.

Aphrodisiac activity of aqueous extract of Anthonotha macrophylla (P. Beauv) leaves in paroxetine-induced sexual dysfunction male Wistar rats

Ethno-pharmacological relevanceAnthonotha macrophylla, a plant with extensive ethnomedicinal uses, has various parts attributed to healing properties. The bark is claimed to be used to treat venereal diseases while the roots are used to treat intestinal discomfort. Gum extract from the bark provides pain relief, while the leaves are used for treating gonorrhoea, diarrhoea, and malaria. Additionally, the leaves are believed to enhance sexual behaviour. Although the age-long folkloric use of Anthonotha macrophylla leaf as aphrodisiac in female rats was substantiated with scientific evidence, the study did not account for the aphrodisiac activity in paroxetine-induced sexual dysfunction in male rat model. Aim of the studyThis study investigated the aphrodisiac activity of aqueous extract of Anthonotha macrophylla leaves (AEAML) in paroxetine-induced sexual dysfunction male rats (PISDMR). Materials and methodsForty-two male rats (144.86 ± 1.21 g) were assigned into six groups (A-F). Group A received distilled water only, while PISDMR in Groups B, C, D, E and F received distilled water, 7.14 mg/kg body weight of sildenafil citrate (reference drug), 25, 50 and 100 mg/kg body weight of AEAML once daily for 7 days. Data were analyzed using a one-way Analysis of Variance (ANOVA) and Tukey's post-hoc test at a 5% level of significance after the determination of male sexual behaviour parameters and associated biochemical indices. ResultsAEAML contained 8 mineral elements and 14 amino acids; potassium (368.24 mg/100g) and glycine (352.70 mg/100g) were the most abundant while cadmium (0.01 mg/100g) and histidine (0.70 mg/100g) were the least. Administration of paroxetine prolonged/increased (p < 0.05) the mount latency (ML), intromission latency (IL), ejaculation latency (EL), post-ejaculatory interval (PEI), and lowered/reduced (p < 0.05) the mount frequency (MF), intromission frequency (IF) and ejaculation frequency (EF). Paroxetine also decreased the weight of the caudal epididymis, seminal vesicle, ventral prostate, and testis, levels of dihydrotestosterone (DHT), testosterone, luteinizing hormone (LH), follicle stimulating hormone (FSH), dopamine, acetylcholine (ACH), nitric oxide (NO), cyclic guanosine monophosphate (cGMP) and increased the levels of serotonin, γ-aminobutyric acid (GABA), phosphodiesterase V (PDE V) and acetylcholinesterase (AChE) of the animals. In contrast, AEAML significantly (p < 0.05) lowered/reduced the paroxetine-induced related increases in the ML, IL, EL, PEI, and prolonged/increased (p < 0.05) the paroxetine-induced related decreases in the MF, IF and EF. The AEAML also reversed (p < 0.05) the paroxetine-induced related decreases in the weight of the caudal epididymis, seminal vesicle, ventral prostate, testis, levels of DHT, testosterone, LH, FSH, dopamine, ACH, NO, cGMP and the paroxetine-induced related increases in the levels of serotonin, GABA, PDE V and AChE. ConclusionAEAML contains aphrodisiac bioactive agents that can be explored as drug lead for MSD.

Combination of low doses of mirtazapine plus venlafaxine produces antidepressant-like effects in rats, without affecting male or female sexual behavior.

Pharmacological treatments for depression are not always effective and produce unwanted side effects. Male and female sexual dysfunction is one of these side effects, which can lead to treatment withdrawal. Combination of two antidepressants with different mechanisms of action, like mirtazapine (MTZ) and venlafaxine (VLF) have been shown to be effective for treatment-resistant depression in humans. Combination of low doses of these drugs may still exert antidepressant-like effects without altering sexual behavior. To investigate the potential antidepressant-like effect of the chronic administration of low doses of MTZ plus VLF combined, as well as its impact on male and female sexual behavior in rats. The antidepressant-like effect of a 14-day treatment with combinations of MTZ plus VLF (0/0, 2.5/3.75 or 5/7.5mg/kg) was assessed in young adult male and female rats in the forced swim test (FST). The 5/7.5mg/kg MTZ/VLF combination was also tested in the chronic mild stress (CMS) test, in both males and females treated for 21days. The sexual effects of this last treatment were assessed in sexually experienced males and in gonadally-intact females during proestrus. The 5/7.5mg/kg MTZ/VLF combination produced an antidepressant-like effect in the FST and reversed the CMS-induced anhedonia in both male and female rats. This combination did not alter male sexual behavior, female proceptive and receptive behaviors or the regularity of the estrous cycle. The combination of low doses of MTZ and VLF might be a promising therapeutic alternative to treat depression without affecting the sexual response.

Developmental exposure to environmentally relevant doses of phthalates alters the neural control of male and female reproduction in mice

The present study aims to analyze the effects of developmental exposure to phthalates at environmentally relevant doses on the neural control of male and female reproduction. For this purpose, C57Bl/6J mice were exposed to di-(2-ethylexyl) phthalate (DEHP) alone (5 or 50 μg/kg/d), or DEHP (5 μg/kg/d) in a phthalate mixture. Exposure through diet started 6 weeks before the first mating and lasted until weaning of litters from the second gestation (multiparous dams). Analyses of offspring born from multiparous dams exposed to DEHP alone or in a phthalate mixture showed that females experienced a delayed pubertal onset, and as adults they had prolonged estrous cyclicity and reduced Kiss1 expression in the preoptic area and mediobasal hypothalamus. Male littermates showed a reduced anogenital distance and delayed pubertal onset compared with controls. However, in adulthood the weight of androgen-sensitive organs and hypothalamic Kiss1 expression were unaffected, suggesting normal functioning of the male gonadotropic axis. Developmental exposure to DEHP alone or in a phthalate mixture reduced the ability of intact males and ovariectomized and hormonally primed females to attract a sexual partner and to express copulatory behaviors. In addition, females were unable to discriminate between male and female stimuli in the olfactory preference test. Social interaction was also impaired in females, while locomotor activity and anxiety-like behavior in both sexes were unaffected by the treatment. The sexual deficiencies were associated with reduced expression of the androgen receptor in the preoptic area and progesterone receptor in the mediobasal hypothalamus, the key regions involved in male and female sexual behavior, respectively. Thus, the neural structures controlling reproduction are vulnerable to developmental exposure to phthalates at environmentally relevant doses in male and female mice. Adult females had an impaired gonadotropic axis and showed more affected behaviors than adult males.

Analysis of single nucleotide polymorphisms of the metabotropic glutamate receptors in a transgender population.

Gender incongruence (GI) is characterized by a marked incongruence between an individual's experienced/expressed gender and the assigned sex at birth. It includes strong displeasure about his or her sexual anatomy and secondary sex characteristics. In some people, this condition produces a strong distress with anxiety and depression named gender dysphoria (GD). This condition appears to be associated with genetic, epigenetics, hormonal as well as social factors. Given that L-glutamate is the major excitatory neurotransmitter in the central nervous system, also associated with male sexual behavior as well as depression, we aimed to determine whether metabotropic glutamate receptors are involved in GD. We analyzed 74 single nucleotide polymorphisms located at the metabotropic glutamate receptors (mGluR1, mGluR3, mGluR4, mGluR5, mGluR7 and mGluR8) in 94 transgender versus 94 cisgender people. The allele and genotype frequencies were analyzed by c2 test contrasting male and female cisgender and transgender populations. The strength of the associations was measured by binary logistic regression, estimating the odds ratio (OR) for each genotype. Measurement of linkage disequilibrium, and subsequent measurement of haplotype frequencies were also performed considering three levels of significance: P ≤ 0.05, P ≤ 0.005 and P ≤ 0.0005. Furthermore, false positives were controlled with the Bonferroni correction (P ≤ 0.05/74 = 0.00067). After analysis of allele and genotypic frequencies, we found twenty-five polymorphisms with significant differences at level P ≤ 0.05, five at P ≤ 0.005 and two at P ≤ 0.0005. Furthermore, the only two polymorphisms (rs9838094 and rs1818033) that passed the Bonferroni correction were both related to the metabotropic glutamate receptor 7 (mGluR7) and showed significant differences for multiple patterns of inheritance. Moreover, the haplotype T/G [OR=0.34 (0.19-0.62); P<0.0004] had a lower representation in the transgender population than in the cisgender population, with no evidence of sex cross-interaction. We provide genetic evidence that the mGluR7, and therefore glutamatergic neurotransmission, may be involved in GI and GD.

Acute ethanol disrupts conditioned inhibition in the male rat.

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. 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. 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 0.5g/kg or 1g/kg, 45min 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. 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. 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.

Sub-acute exposure of male guppies (Poecilia reticulata) to environmentally relevant concentrations of PFOA and GenX induces significant changes in the testis transcriptome and reproductive traits

Poly- and perfluoroalkyl substances (PFAS) are frequently detected in the environment and are linked to adverse reproductive health outcomes in humans. Although legacy PFAS have been phased out due to their toxicity, alternative PFAS are increasingly used despite the fact that information on their toxic effects on reproductive traits is particularly scarce. Here, we exposed male guppies (Poecilia reticulata) for a short period (21 days) to an environmentally realistic concentration (1 ppb) of PFOA, a legacy PFAS, and its replacement compound, GenX, to assess their impact on reproductive traits and gene expression. Exposure to PFAS did not impair survival but instead caused sublethal effects. Overall, PFAS exposure caused changes in male sexual behaviour and had detrimental effects on sperm motility. Sublethal variations were also seen at the transcriptional level, with the modulation of genes involved in immune regulation, spermatogenesis, and oxidative stress. We also observed bioaccumulation of PFAS, which was higher for PFOA than for GenX. Our results offer a comprehensive comparison of these two PFAS and shed light on the toxicity of a newly emerging alternative to legacy PFAS. It is therefore evident that even at low concentrations and with short exposure, PFAS can have subtle yet significant effects on behaviour, fertility, and immunity. These findings underscore the potential ramifications of pollution under natural conditions and their impact on fish populations.

787 Higher County-Level Socioeconomic Status Is Associated With Increased Meningioma Survival But Does Not Impact Likelihood of Surgical Treatment: A CBTRUS Analysis

INTRODUCTION: Prior literature suggests that individual socioeconomic status (SES) may influence access to treatment and outcomes for primary brain tumors. To date, no population-level studies have assessed the correlation between meningioma treatment and outcome with county-level SES. METHODS: Incidence data were extracted from the Central Brain Tumor Registry of the United States(CBTRUS), a combined dataset including the CDC’s National Program of Cancer Registries (NPCR) and NCI’s Surveillance, Epidemiology, and End Results Program data, for diagnosis years 2006-2019, and survival data were extracted from the NPCR survival analytic dataset from 2006-2018. SES quintiles were created using American Community Survey data. Logistic regression and Cox proportional hazards models were used to assess the relationship the odds of receiving treatment and overall survival and SES and the individual SES factors. RESULTS: There were 409,681 meningioma cases available from CBTRUS. Asian/Pacific-Islander non-Hispanic individuals (odds ratio [OR] = 1.28, p &lt; 0.001) were more likely and Black non-Hispanic (BNH) individuals (OR = 0.90, p &lt; 0.001) were less likely to receive surgery than White non-Hispanic (WNH) individuals. Female sex (OR = 1.31, p &lt; 0.001), living in a metropolitan area (OR = 0.96, p &lt; 0.001), and increased age at diagnosis (OR = 0.96, p &lt; 0.001) were associated with decreased likelihood of surgery. There was no association between SES and likelihood to receive surgery. Overall median survival was 137 months and survival was higher in higher SES counties, which held true for both WNH and BNH. Age at diagnosis(hazard ratio [HR] = 1.01, p &lt; 0.001), male sex (HR = 1.51, p &lt; 0.001), BNH (HR = 1.31, p &lt; 0.001), subtotal resection (HR = 1.38, p &lt; 0.001), and malignant behavior(HR = 1.64, p &lt; 0.001) were associated with increased hazard of death. CONCLUSIONS: In the US, county-level SES did not impact treatment patterns, but higher SES was associated with increased survival. These findings provide valuable insight into socioeconomic factors influencing treatment and outcomes in meningioma patients.

Effect of Curcuma longa extract on reproduction function in mice and testosterone production in Leydig cells.

Curcuma longa, best known for its culinary application as the main constituent of curry powder, has shown potential impact on the reproductive system. This study aimed to investigate the efficacy of Curcuma longa extract (CLE) on Kidney-Yang deficiency mice induced by hydrocortisone and the possible roles in testosterone secretion in Leydig cells. We evaluated male sexual behaviour, reproductive organ weight, testosterone levels, and histological tissue changes in hydrocortisone-induced mice. CLE effectively reversed hydrocortisone-induced Kidney-Yang deficiency syndrome by improving sexual behaviour, testis and epididymis weight, testosterone levels and reducing pathological damage. Our invitro study further indicated that CLE stimulated testosterone production via upregulating the mRNA and protein expression of steroidogenic enzymes in Leydig cells. It significantly improved H89-inhibited protein expression of StAR and cAMP-response element-binding (CREB), as well as melatonin-suppressed StAR protein expression. The data obtained from this study suggest that CLE could alleviate Kidney-Yang deficiency symptoms and stimulate testosterone production by upregulating the steroidogenic pathway. This research identifies CLE as a potential nutraceutical option for addressing testosterone deficiency diseases.

Neurogenomic landscape associated with status-dependent cooperative behaviour.

The neurogenomic mechanisms mediating male-male reproductive cooperative behaviours remain unknown. We leveraged extensive transcriptomic and behavioural data on a neotropical bird species (Pipra filicauda) that performs cooperative courtship displays to understand these mechanisms. In this species, the cooperative display is modulated by testosterone, which promotes cooperation in non-territorial birds, but suppresses cooperation in territory holders. We sought to understand the neurogenomic underpinnings of three related traits: social status, cooperative display behaviour and testosterone phenotype. To do this, we profiled gene expression in 10 brain nuclei spanning the social decision-making network (SDMN), and two key endocrine tissues that regulate social behaviour. We associated gene expression with each bird's behavioural and endocrine profile derived from 3 years of repeated measures taken from free-living birds in the Ecuadorian Amazon. We found distinct landscapes of constitutive gene expression were associated with social status, testosterone phenotype and cooperation, reflecting the modular organization and engagement of neuroendocrine tissues. Sex-steroid and neuropeptide signalling appeared to be important in mediating status-specific relationships between testosterone and cooperation, suggesting shared regulatory mechanisms with male aggressive and sexual behaviours. We also identified differentially regulated genes involved in cellular activity and synaptic potentiation, suggesting multiple mechanisms underpin these genomic states. Finally, we identified SDMN-wide gene expression differences between territorial and floater males that could form the basis of 'status-specific' neurophysiological phenotypes, potentially mediated by testosterone and growth hormone. Overall, our findings provide new, systems-level insights into the mechanisms of cooperative behaviour and suggest that differences in neurogenomic state are the basis for individual differences in social behaviour.

The effects of 17β-trenbolone and bisphenol A on sexual behavior and social dominance via the hypothalamic-pituitary-gonadal axis in male mice

17β-Trenbolone (17-TB) is well documented as an environmental endocrine disruptor in aquatic biological studies, but its effects on mammals remain poorly understood. Furthermore, 17-TB acts as a hormone with properties similar to testosterone, and the consequences of juvenile exposure on adult social behavior remain uncertain. Bisphenol A (BPA) acts as an estrogen-like hormone, compared to 17-TB. Three-week-old male Balb/c mice were exposed orally to 17-TB (100 µg/(kg·day)) and BPA (4 mg/(kg·day)) for 28 days. Assessments of social interactions and a three-chamber test showed that 17-TB increased virility in male mice, intensified both male and female sexual behavior, and attracted and accepted female mice. It also increased social dominance through tube tests in male mice and markedly activated the c-Fos+ immune response in the medial prefrontal cortex (mPFC) and basal amygdala (BLA). ELISA data showed that 17-TB and BPA exposure significantly affected serum gonadotropin-releasing hormone (GnRH), growth hormone (GH), estradiol (E2), and luteinizing hormone (LH) levels, as well as testicular lesions and androgen receptor (ARβ) and estrogen receptor (ERα) synthesis. Testicular transcriptomic analysis further confirmed that could disrupt steroid synthesis and linoleic acid-related biometabolic processes. These findings suggest the influence of 17-TB and BPA exposure on sexual behavior and fertility in male mice, possibly through modulation of the hypothalamic-pituitary-gonadal axis. This study provides insights relevant to human reproductive health and neuro-social behavioral research, and the potential risk of environmental disturbances should not be overlooked.

Effects of chronic mild stress induced from peripuberty on sexual behavior in male rats, with or without escitalopram treatment.

After the Coronavirus Disease pandemic, depression became more present, including in adolescents. Escitalopram, a selective serotonin reuptake inhibitor, was approved in 2009 for treatment of the major depressive disorder, both in children and adolescents. The undesirable effects of antidepressants on sexual dysfunction are usually underestimated. To investigate the effects of chronic mild stress, induced from peripuberty up to adulthood, on male sexual behavior parameters, with or without the escitalopram treatment, using rats as experimental model in a translational study. Forty-four peripubertal male rats were distributed into four groups: Sham control, escitalopram, stress, and stress + escitalopram. The chronic mild stress consisted of nine different stressors randomly applied one per day, for 8weeks (from 41 to 97 days postpartum). Escitalopram therapy by gavage (10mg/kg) started at 70 days postpartum and lasted for 4weeks. The male sexual behavior parameters were evaluated at 114 days postpartum. After that, euthanasia was performed for blood and testis collection. Histopathology of the testes and plasmatic testosterone level were carried out. There was a reduction in sexual activity and motivation in rats exposed to the stress protocol, which were treated or not with escitalopram, as well as an increase in the total number of mounts in animals exposed to the stress and treated with escitalopram. The testosterone levels were lower in animals exposed to the stress, which were or not treated with escitalopram (stress and stress + escitalopram). The frequency of histologically normal seminiferous tubule sections was lower in animals that were exposed to the stress and/or received escitalopram (escitalopram, stress, and stress + escitalopram). Chronic mild stress induced from peripuberty, associated or not to escitalopram treatment, altered the testosterone levels and testicular histoarchitecture and seems to be related to the reduction in male sexual motivation.

No fitness effects of same-sex copulations in male red flour beetles.

Same-sex sexual behavior occurs in diverse animal taxa, yet its evolutionary maintenance is poorly understood as such behavior seems to be costly and does not directly increase reproductive success. We used male Tribolium castaneum beetles, which frequently engage in same-sex copulations, to test if same-sex sexual behavior influences future male mating behavior and reproductive success of males. Furthermore, we tested whether same-sex sexual behavior has benefits via indirect sperm translocation. We conducted a series of mating trials demonstrating that males exposed to same-sex behavior did not sire less offspring compared to control males that did not engage in same-sex behavior. This suggests that same-sex copulations did not lead to fitness costs in subsequent mating interactions. In addition, we found no evidence that indirect sperm translocation via an intermediate male occurs in T. castaneum. Taken together, these results imply that same-sex sexual behavior in males is associated with no costs in terms of lower mating rate and reduced siring success and does not seem to entail benefits. Moreover, our data conform to the hypothesis that sexual indiscrimination is prevalent in this species, which may explain the relatively high frequency of same-sex sexual behavior in T. castaneum.

Neural Circuitry Involving Substance P in Male Sexual Behavior.

Neural Circuitry Involving Substance P in Male Sexual Behavior.

Design and test of novel scent enrichments to enhance breeding of zoo-housed lemurs.

Zoos use environmental enrichments, including scents, which may have applications to improve breeding success for taxa, such as lemurs, which rely heavily on olfactory communication. We aimed to develop novel, biologically-relevant scent enrichments to trigger mating behaviours of zoo-housed lemur species, which are critically endangered in the wild and show a low success rate in captive breeding programmes. We examined anogenital odour secretions, released by female gentle ( Hapalemur alaotrensis) and ruffed ( Varecia variegata) lemurs, using solid-phase microextraction and gas chromatography-mass spectrometry techniques. We identified the key compounds distinguishing the volatile chemical profile of female lemurs during the breeding season and used them to develop species-specific scent enrichments. We then tested the scent enrichments, made up of synthesized mixtures conveying information about female lemur fertility, on unsuccessful breeding pairs of lemurs hosted in European zoos. We evaluated the effects of the newly designed scent enrichments on their target species by combining behavioural observations with faecal endocrinology. We identified and reproduced fertility-specific signals associated with female scents. These scent mixtures triggered male sexual behaviours, including mating, during and after the enrichment condition. We also found effects on faecal testosterone levels, with increased levels after the enrichment condition albeit not statistically significant. Our findings suggest that biologically-relevant scent enrichments may trigger natural species-specific behaviours, with potential implications for conservation breeding of zoo-based endangered lemur species, and highlight that combining more assessment methods may assist with evaluating the impact of environmental enrichments.

Can exposure to lisdexamfetamine dimesylate from juvenile period to peripubertal compromise male reproductive parameters in adult rats?

Lisdexamfetamine (LDX) is a d-amphetamine prodrug used to treat attention deficit and hyperactivity disorder, a common neurodevelopmental disorder in children and adolescents. Due to its action mediated by elevated levels of catecholamines, mainly dopamine and noradrenaline, which influence hormonal regulation and directly affect the gonads, this drug may potentially disrupt reproductive performance. This study evaluated the effects of exposure to LDX from the juvenile to peripubertal period (critical stages of development) on systemic and reproductive toxicity parameters in male rats. Male Wistar rats (23 days old) were treated with 0; 5.2; 8.6 or 12.1 mg/kg/day of LDX from post-natal day (PND) 23 to 53, by gavage. LDX treatment led to reduced daily food and water consumption, as well as a decrease in social behaviors. The day of preputial separation remained unaltered, although the treated animals exhibited reduced weight. At PND 54, the treated animals presented signs of systemic toxicity, evidenced by a reduction in body weight gain, increase in the relative weight of the liver, spleen, and seminal gland, reduction in erythrocyte and leukocyte counts, reduced total protein levels, and disruptions in oxidative parameters. In adulthood, there was an increase in immobile sperm, reduced sperm count, morphometric changes in the testis, and altered oxidative parameters, without compromising male sexual behavior and fertility. These findings showed that LDX-treatment during the juvenile and peripubertal periods induced immediate systemic toxicity and adversely influenced reproductive function in adult life, indicating that caution is necessary when prescribing this drug during the peripubertal phase.

Early Female Transgender Identity after Prenatal Exposure to Diethylstilbestrol: Report from a French National Diethylstilbestrol (DES) Cohort.

Diagnostic of transsexualism and gender incongruence are terms to describe individuals whose self-identity does not match their sex assignment at birth. A transgender woman is an individual assigned male at birth (AMAB) on the basis of the external or internal genitalia who identifies and lives as a woman. In recent decades, a significant increase in the number of transgender people has been reported. Although, its etiology is unknown, biological, anatomical, genetic, environmental and cultural factors have been suggested to contribute to gender variation. In XY animals, it has been shown that environmental endocrine disruptors, through their anti-androgenic activity, induce a female identity. In this work, we described four XY individuals who were exposed in utero to the xenoestrogen diethylstilbesterol (DES) and were part of the French HHORAGES cohort. They all reported a female transgender identity starting from childhood and adolescence. This high prevalence of male to female transgenderism (1.58%) in our cohort of 253 DES sons suggests that exposure to chemicals with xenoestrogen activity during fetal life may affect the male sex identity and behavior.