Decrease In Sexual Behavior Research Articles

A review of antioxidant strategies to improve reproduction in aging male broiler breeders.

As only 10% of the broiler breeder flock is roosters, their fertility is very important. The rooster sperm plasma membrane has high concentrations of polyunsaturated fatty acids that are sensitive to oxidative stress. Lipid peroxidation can change membrane structure, permeability, and fluidity, adversely affecting the acrosome reaction and fertility. Aging roosters have decreases in sexual behavior, serum androgen concentrations, sperm quantity and quality, and fertility. Low fertility in aging roosters is attributed to an imbalanced testicular oxidant-antioxidant system, with increased reactive oxygen species (ROS) damaging spermatogenic epithelium. However, antioxidant components can enhance antioxidant defenses in aging broiler breeder roosters. Protection against oxidative damage, particularly in the testes, improves reproductive hormone concentrations, testicular histology, sperm membrane function, and mitochondrial activity and thereby improves semen volume, sperm concentration, viability, motility, and sperm polyunsaturated fatty acid content, sperm-egg penetration, fertility, and reproductive performance. This review summarizes antioxidants that could improve fertility and reproductive performance and delay or prevent age-related declines in broiler breeder roosters, with benefits for poultry production.

Effect of Arthrospira (Spirulina) maxima on Cadmium-Chloride-Induced Alterations in Sexual Behavior and Fertility in Male Wistar Rats.

Chronic exposure to potentially toxic elements (PTEs) such as cadmium (Cd) leads to male reproductive toxicity through the generation of oxidative stress. Spirulina Arthrospira maxima (AM) is a cyanobacterium that has been consumed since ancient times for its high nutritional value, and in recent years for its antiviral, hepatoprotective, hypoglycemic, anticancer, and antioxidant effects, among others. This study aimed to evaluate the effects of AM against the damage to reproductive health induced by Cd. A total of 48 10-week-old sexually experienced male Wistar rats were distributed in five groups (n = 8): control; vehicle (tween-water); cadmium chloride (CdCl2) 5 mg/kg; and three doses of AM (100, 200 and 400 mg/kg) + CdCl2 5 mg/kg. All treatments were orally administered once a day for 36 consecutive days. At the end, sexual behavior was evaluated, and semen, testicle, and blood samples were obtained to analyze sperm quality, enzymatic activity, and testosterone levels, respectively. Rats exposed to Cd showed a decrease in sexual behavior, as well as in the quality of reproductive health, and an increase in oxidative stress; while rats exposed simultaneously to AM + Cd showed an improvement in all this parameters. Based on our results, we believe that the mechanism by which AM exerts its effect could be attributed to the presence of phycobiliproteins. These compounds are responsible for exerting an antioxidant effect and chelating effect on elements such as Cd.

Modifications to Sexual Behaviors Associated With Mpox (Monkeypox) Virus Transmission Among Persons Presenting for mpox Vaccination, Washington, DC, August-October, 2022.

Over 30,000 mpox cases were reported during the 2022 mpox outbreak with many cases occurring among gay, bisexual and other men who have sex with men (MSM). Decreases in U.S. mpox cases were likely accelerated by a combination of vaccination and modifications to sexual behaviors associated with mpox virus transmission. We assessed reports of sexual behavior change among participants receiving mpox vaccination in Washington, DC. During August to October 2022, 711 adults aged ≥18 years receiving mpox vaccination at two public health clinics in Washington, DC completed a self-administered questionnaire that asked whether sexual behaviors changed since learning about mpox. We calculated the frequency and percentages of participants reporting an increase, decrease, or no change in 4 of these behaviors by demographic, clinical, and behavioral characteristics with 95% confidence intervals. Overall, between 46% and 61% of participants reported a decrease in sexual behaviors associated with mpox virus transmission, 39% to 54% reported no change in these behaviors, and <1% reported an increase. Approximately 61% reported decreases in one-time sexual encounters (95% confidence interval [CI], 56.8%-64.7%), 54.3% reduced numbers of sex partners (95% CI, 50.4%-58.0%), 53.4% decreased sex via a dating app or sex venue (95% CI, 49.7%-58.0%), and 45.6% reported less group sex (95% CI, 40.4%-50.9%). Reported decreases in these behaviors were higher for MSM than women; in non-Hispanic Black than non-Hispanic White participants; and in participants with human immunodeficiency virus than participants without human immunodeficiency virus. Most participants receiving mpox vaccination reported decreasing sexual behaviors associated with mpox virus transmission, including groups disproportionately affected by the outbreak.

Reproductive disruption in adult female and male rats prenatally exposed to mesquite pod extract or daidzein

Phytoestrogens are considered to be endocrine disruptors, since they can alter the endocrine system, thus disturbing many reproductive events. The intake of diets containing a high content of phytoestrogens has increased worldwide in human populations and in domestic animals. Phytoestrogens in maternal blood can pass through the placenta to the fetus in high amounts and can have long-term organizational effects. Mesquite (Prosopis sp) is a leguminous plant widely used to feed several livestock species, and is also used in the human diet. In this study we assessed the effects of exposure to mesquite pod extract during the periconception and pregnancy periods on the reproduction of male and female descendants. The females of three experimental groups received one of the following treatments: 1) vehicle injection; 2) mesquite pod extract or 3) the isoflavone daidzein during the periconception and pregnancy periods. Estrous cyclicity, sexual behavior and hormones, as well as uterine and vaginal epithelia were evaluated in the female descendants. In the males, sexual behavior and hormones, apoptosis in testicular cells and sperm quality were evaluated. In females the following was observed: alterations in estrous cycles, decreased sexual behavior, estradiol and progesterone levels, increased uterine and vaginal epithelia. In males, we observed a decrease in sexual behavior, testosterone and sperm quality, and apoptosis increased in testicular cells. All these effects were similar to those caused by daidzein. These results indicate that prenatal exposure to mesquite pod extract or daidzein, administered to females before and during pregnancy, can disrupt normal organizational-activational programming of reproductive physiology in female and male descendants.

Longitudinal Assessment of Changes in Mental and Sexual Health Outcomes Due to COVID-19 Among Latinx SMM and TGW.

Longitudinal Assessment of Changes in Mental and Sexual Health Outcomes Due to COVID-19 Among Latinx SMM and TGW.

The organizational effects of pubertal testosterone on sexual proficiency in adult male Syrian hamsters

Social proficiency requires making appropriate behavioral adaptations as a result of social experience. For example, male rodents become sexually proficient with experience as demonstrated by a reduction in ectopic (misdirected) mounts, mount-to-intromission ratio, and latency to ejaculation. We previously found that over a series of timed tests with a receptive female, male hamsters deprived of testosterone specifically during puberty (NoT@P) have overall lower levels of sexual behavior and continue to display high levels of ectopic mounts, compared with males that experienced endogenous testosterone during puberty (T@P). These results suggested that pubertal testosterone programs sexual proficiency in adulthood, but because NoT@P males engaged in less sexual behavior than T@P males in these tests, the amount of sexual experience may have been insufficient to improve sexual proficiency. To more rigorously test the hypothesis that pubertal testosterone is necessary for social proficiency in adulthood, the present study compared the behavior of NoT@P and T@P males in a series of 4 trials with a 48-h interval between each trial. Sexual experience was equated by limiting each trial to 5 intromissions. Sexually-naïve males were either gonadectomized prepubertally (NoT@P) or in adulthood (T@P) and received subcutaneous testosterone capsules four weeks later. Two weeks after testosterone replacement, these groups and a group of adult gonad-intact controls began sexual behavior testing. We found that NoT@P males had more ectopic mounts/min across all four tests compared to gonad-intact and T@P males. Moreover, both gonad-intact and T@P males, but not NoT@P males, showed an increase in the number of mounts and intromissions/min between trials 1 and 3. Unexpectedly, both gonad-intact and T@P, but not NoT@P, males showed a decrease in sexual behaviors during trial 4. Thus, T@P males display multiple behavioral adaptations to sexual experience that are not observed in NoT@P males: a reduction in ectopic mounts after repeated encounters with a receptive female and an inverted U-shape pattern in mounts and intromissions when these encounters do not lead to ejaculations. These results support the hypothesis that pubertal testosterone organizes neural circuits underlying behavioral flexibility and adaptability to promote sexual proficiency in adulthood.

Overweight male juvenile rats exhibit decreases in sexual behavior and serum testosterone levels and an increase in TNF-α levels in adulthood.

Overweight male juvenile rats exhibit decreases in sexual behavior and serum testosterone levels and an increase in TNF-α levels in adulthood.

Vilazodone does not inhibit sexual behavior in male rats in contrast to paroxetine: A role for 5-HT1A receptors?

Vilazodone (VLZ) is a selective serotonin reuptake inhibitor (SSRI) and 5-HT1A receptor partial agonist approved for the treatment of major depressive disorder in adults. In preclinical studies, VLZ had significantly lower sexual side effects than SSRIs and reduced serotonin transporter (SERT) levels in forebrain regions. In the current study, once-daily paroxetine (PAR, 10 mg/kg), VLZ (10 mg/kg), PAR + buspirone (BUS, 3 mg/kg; a 5-HT1A partial agonist), or vehicle (VEH) was administered to male rats for 2 weeks then switched for 7 days (eg, PAR switched to VLZ, PAR + BUS, or VEH). Sexual behavior (eg, ejaculation frequency and latency) was evaluated 1-hr postdose on days 1, 7, 14, and 21. After 2 weeks, treatment with PAR but not VLZ resulted in a significant decrease in sexual behavior. In a 30-min test, the range of ejaculation frequency was 3.08–3.5 with VLZ and 1.00–1.92 with PAR (P < 0.05 vs VEH). After switching from PAR to VEH, PAR + BUS, or VEH, sexual behaviors were normalized to control levels. In contrast, the switch from VLZ to PAR resulted in reduced sexual behaviors. This preclinical study showed that unlike PAR, an SSRI with no 5-HT1A receptor activity, initial treatment with VLZ did not result in sexual side effects at therapeutically relevant doses. Results in male rats switched from PAR to VLZ or PAR + BUS strongly suggest that activation of 5-HT1A receptors may mitigate the sexual side effects associated with conventional SSRIs.

Reproductive Dysfunction in Female Rats With Renovascular Hypertension

Hypertension is a major public health epidemic that is highly associated with sexual dysfunction in both men and women. Despite its high prevalence, clinical and animal literature on the underlying mechanisms of sexual dysfunction in hypertensive women is remarkably limited. Using a well-established rodent model of renovascular hypertension-the 2-kidney, 1-clip (2K1C) Goldblatt model-we investigated possible reproductive deficits in female rats. We evaluated several aspects of reproductive function in hypertensive female rats: estrous cycle, sexual behavior, ovulation, and plasma levels of luteinizing hormone (LH), follicle-stimulating hormone (FSH), and estradiol at proestrus afternoon. Clipping of the left renal artery resulted in dramatic elevations in systolic blood pressure and heart rate. Renovascular hypertension was associated with a delay for reestablishing estrous cyclicity (50% of 2K1C rats failed to resume cycling by 15 days after surgery). In rats that resumed cycling, 2K1C female rats showed a decrease in sexual behavior, evidenced by a decreased lordosis quotient and a reduction in ovulation, as demonstrated by a decreased number of oocytes. Moreover, plasma levels of LH on the proestrus afternoon were reduced in hypertensive female rats, but no changes in estradiol or FSH were observed. Our results demonstrate that renovascular hypertension induces an overall decrease in reproductive function in female rats. Most important, our results indicate that the animal model of renovascular hypertension could be used as a relevant tool to understand better the pathophysiological mechanisms involved in the reproductive deficits in women with renovascular hypertension.

Depression Symptoms and Sexual HIV Risk Behavior Among Serodiscordant Couples

To examine data for human immunodeficiency virus (HIV)-positive patients in serodiscordant relationships to determine a) if depressive symptoms were associated with sexual risk behavior and b) if these relationships could be explained by changes in partner satisfaction. The relationship between depression symptoms and sexual risk behaviors within mixed HIV status couples is unknown. HIV-positive and HIV-negative members of 197 serodiscordant couples (159 male/female, 38 male/male) were assessed using instruments measuring depressive symptoms, sexual risk, and couple satisfaction. HIV-positive partners with higher depression scores were less likely to be part of couples reporting unprotected sex, and HIV-positive partners' higher depression scores were associated with less unprotected intradyadic sex acts. This decrease in intradyadic sexual risk behavior was partially explained by a decrease in any sexual behavior within the couple. On the other hand, HIV-positive subjects with moderate or higher depression were more likely to have outside partners. Adding the partner satisfaction measure to the models was able to account for the relationship between the HIV-positive subjects' depression scores and outside partners, but not for that between higher depression score and reduced intradyadic sexual risk. HIV-positive individuals with more depressive symptoms may be less likely to engage in high-risk sexual behavior with their partners than those with less depressive symptoms, but more likely to have sexual partners outside the relationship. These findings suggest that the relationship between depressive symptoms and sexual risk behavior in this population may be mixed and complex, and suggest that clinicians should assess sexual risk behavior across the range of depression symptom severity.

Progesterone Inhibits Female Courtship Behavior in Domestic Canaries (Serinus canaria)

We studied copulation solicitation display (CSD) responses to playback in photostimulated female canaries given systemic injections of progesterone. Eight females received injections of 0.1 mg of progesterone dissolved in olive oil during their first breeding cycle and were untreated during their second breeding cycle; eight females received only the oil vehicle during their first breeding cycle and received no treatment during their second breeding cycle. The injections were performed every second day during 15 days, after the onset of nest building. Progesterone treatment resulted in a significant increase of plasma progesterone which in turn provoked an inhibition of females' CSDs and decreased the size of the clutch. During the first breeding cycle, progesterone-treated females had lower CSDs and egg-laying scores than did control females. During the second breeding cycle, when females received no treatment, no differences emerged between the two groups. The suppressive effect of progesterone on female sexual responses was observed as soon as 48 h after the beginning of the treatment. We propose that progesterone plays a key role in mediating the transition from active female courtship behavior to sexual refractoriness in this species. Suppressive effects of progesterone on female sexual behavior have been previously described in lizards as well as in rodents. Our data are consistent with the hypothesis of Godwin et al. (J. Godwin, V. Hartman, M. Grammer, and D. Crews, Horm. Behav. 30, 138–144, 1996) which proposed that the decrease in sexual behavior following plasma progesterone increase represents an evolutionarily conserved mechanism in the regulation of female sexual behavior.

Effect of Vomeronasal Organ Removal on Male Socio-Sexual Responses to Female in a Prosimian Primate ( Microcebus murinus)

In most mammals, olfactory cues play an important role in regulating socio-sexual behaviors, but the relative contributions of the main olfactory system and the vomeronasal system remain unclear. The lesser mouse lemur, a nocturnal prosimian, possesses well-developed chemosensory structures, including a functional vomeronasal organ (VNO). In this primitive primate, social communication and competition between males for priority access to receptive females includes reliance on urinary chemical cues. To assess the role of the VNO in mediating males’ behavioural responses to females, sexually-experienced intact males (C, n = 8) or males deprived of their VNO (VNX, n = 8) were put in pairs and their socio-sexual behaviors in response to a preoestrous female were monitored. Independent of social context (with or without female), VNX males exhibited less sniffing behaviors than C males, but their marking behaviors, although reduced, were not significantly different. Removal of the VNO dramatically reduced the frequency of both sexual behaviors (anogenital investigations, mounts) and intermale aggressive behaviors. However, VNO removal did not impair successful mating and had no effect on plasma testosterone levels. Lastly, VNX males always exhibited a significantly lower general activity level than C males. The decrease in sexual behaviors and the lack of aggressive intermale competition in responses to a preoestrous female possibly proceed from functional disturbances of central nervous areas connected to the vomeronasal system rather than from a chemosensory deficit per se.

Concurrent wet dog shaking and inhibition of male rat copulation after ventromedial brainstem injection of the 5-HT2 agonist DOI

Systemic administration of drugs that augment 5-HT2 activity generally induces ‘wet dog’ shaking (WDS) in rats. This suggests that the naturally occurring form of WDS seen in untreated rats may also serve as a behavioral index of 5-HT2 receptor activation, during the performance of other behaviors. Indeed, spontaneously occurring WDS has previously been reported to be inversely related to male rat copulatory proficiency. In order to examine a potential central nervous system mechanism subsuming these behaviors, male rats were tested for WDS and sexual behavior after brainstem administration of the 5-HT2 agonist DOI. Male Long-Evans rats were implanted with cannulae terminating in the region of the nucleus raphe obscurus/inferior olive, through which they received injections of DOI (0.1–10 μg). DOI produced a dose-dependent decrease in sexual behavior and concurrent increase in WDS. Pretreatment with the 5-HT2 antagonist ritanserin effectively blocked the effects of DOI. The results suggest that WDS and copulatory behaviors are modulated by a shared brainstem substrate. It is possible that the results may be the behavioral concomitant of recently described brainstem cells, with bifurcating axons, that project to both the medial preoptic area and the cervical spinal cord.

Sexual behavior of male rats is differentially affected by timing of perinatal ACTH administration

The laboratory rat was used as a model to investigate the effect of pre- and/or postnatal ACTH administration on sexual differentiation of the brain. Pregnant Sprague-Dawley rats were injected with ACTH 1–24 (10 μg/kg/2 × /day or 500 μg/kg/2 × /day); postnatally treated neonates were injected with the above dosages once a day. Perinatal treatment with ACTH (10 μg/kg/2 × /day) altered several sexual behavior measurements, but did not have an overall effect on the number of males that exhibited sexual behavior. At a higher dose (500 μg/kg/2 × /day) prenatal ACTH administration decreased sexual behavior in male rats, as measured by an increase in the percent of males that did not mount or intromit. In contrast, all males treated postnatally with ACTH (500 μg/kg/2 × /day) completed 2 ejaculatory series and initiated a third series. No significant differences were observed in adult plasma testosterone or prolactin levels; however, serotonin levels in the preoptic area of adult male rats treated prenatally with ACTH (500 μg/kg/2 × /day) were significantly higher than in prenatally treated saline males. In addition, an increase in plasma ACTH in adulthood was observed in animals injected postnatally with saline. This study indicates that the decrease in sexual behavior observed in males treated prenatally with ACTH is associated with increased serotonin levels in the preoptic area, which suggests that ACTH may act as a neuromodulator during sexual differentiation of the brain. It also demonstrates that the effect of perinatal manipulations on the development of male sexual behavior may vary depending on the ontogenetic period of the brain.

Castration, sex steroids, and heterosexual behavior in adult male laboratory-housed stumptailed macaques ( Macaca arctoides)

The sociosexual behaviors of six stable male-female pairs of stumptailed monkeys were studied in half-hour pair tests. Their performance before and after castration of the males was compared. The effects of replacement therapy with sex steroids on male-female interaction were studied. Also the effects of new females as sexual partners were investigated. Castration caused a significant decrease in sexual behavior. Individual males could display ejaculatory behavior up to about 1 year postcastration. Dihydrotestosterone propionate (75 mg/week/♂) alone or in combination with estradiol benzoate (0.9 or 3 mg/week/♂) was not effective in restoring sexual behavior to precastration levels in the three castrated males tested. Replacement therapy with testosterone propionate (75 or 10 mg/week/♂) was effective in restoring copulatory behavior in half of the castrated males. In some males the introduction of a new female caused an increase in sexual activity, usually when sexual activity with their familiar partner was low. This occurred both in the castration condition and in the steroid treatment period, suggesting, that low activity was caused by low “motivation” and not by the inability to perform.