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

Reduction of Prostate Cancer Risk: Role of Frequent Ejaculation-Associated Mechanisms

Prostate cancer (PCa) accounts for roughly 15% of diagnosed cancers among men, with disease incidence increasing worldwide. Age, family history and ethnicity, diet, physical activity, and chemoprevention all play a role in reducing PCa risk. The prostate is an exocrine gland that is characterized by its multi-functionality, being involved in reproductive aspects such as male ejaculation and orgasmic ecstasy, as well as playing key roles in the regulation of local and systemic concentrations of 5α-dihydrotestosterone. The increase in androgen receptors at the ventral prostate is the first elevated response induced by copulation. The regulation of prostate growth and function is mediated by an androgen-dependent mechanism. Binding 5-DHT to androgen receptors (AR) results in the formation of a 5α-DHT:AR complex. The interaction of the 5α-DHT:AR complex with the specific DNA enhancer element of androgen-regulated genes leads to the regulation of androgen-specific target genes to maintain prostate homeostasis. Consequently, ejaculation may play a significant role in the reduction of PCa risk. Thus, frequent ejaculation in the absence of risky sexual behavior is a possible approach for the prevention of PCa. In this review, we provide an insight into possible mechanisms regulating the impact of frequent ejaculation on reducing PCa risk.

Do Sex and Gender Have Separate Identities?

The largely binary nature of biological sex and its conflation with the socially constructed concept of gender has created much strife in the last few years. The notion of gender identity and its differences and similarities with sex have fostered much scientific and legal confusion and disagreement. Settling the debate can have significant repercussions for science, medicine, legislation, and people's lives. The present review addresses this debate though different levels of analysis (i.e., genetic, anatomical, physiological, behavioral, and sociocultural), and their implications and interactions. We propose a rationale where both perspectives coexist, where diversity is the default, establishing a delimitation to the conflation between sex and gender, while acknowledging their interaction. Whereas sex in humans and other mammals is a biological reality that is largely binary and based on genes, chromosomes, anatomy, and physiology, gender is a sociocultural construct that is often, but not always, concordant with a person' sex, and can span a multitude of expressions.

Cohabitation with receptive females under D2-type agonism in adulthood restores partner preference and brain dimorphism in the SDN-POA following neonatal gonadectomy in male rats

Perinatal testosterone, or its metabolite estradiol, organize the brain toward a male phenotype. Male rodents with insufficient testosterone during this period fail to display sexual behavior and partner preference for receptive females in adulthood. However, cohabitation with non-reproductive conspecifics under the influence of a D2 agonist facilitates the expression of conditioned partner preference via Pavlovian learning in gonadally intact male rats. In the present experiment, three groups of neonatal PD1 males (N = 12/group) were either gonadectomized (GDX), sham-GDX, or left intact and evaluated for social preferences and sexual behaviors as adults. We then examined whether the effects of GDX could be reversed by conditioning the males via cohabitation with receptive females under the effects of the D2 agonist quinpirole (QNP) or saline, along with the size of some brain regions, such as the sexually dimorphic nucleus of the preoptic area (SDN-POA), suprachiasmatic nucleus (SCN), posterior dorsal medial amygdala (MeApd) and ventromedial hypothalamus (VMH). Results indicated that neonatal GDX resulted in the elimination of male-typical sexual behavior, an increase in same-sex social preference, and a reduction of the area of the SDN-POA. However, GDX-QNP males that underwent exposure to receptive females in adulthood increased their social preference for females and recovered the size in the SDN-POA. Although neonatal GDX impairs sexual behavior and disrupts partner preference and brain dimorphism in adult male rats, Pavlovian conditioning under enhanced D2 agonism ameliorates the effects on social preference and restores brain dimorphism in the SDN-POA without testosterone.

Neurobiology of Pathogen Avoidance and Mate Choice: Current and Future Directions

Animals are under constant threat of parasitic infection. This has influenced the evolution of social behaviour and has strong implications for sexual selection and mate choice. Animals assess the infection status of conspecifics based on various sensory cues, with odours/chemical signals and the olfactory system playing a particularly important role. The detection of chemical cues and subsequent processing of the infection threat that they pose facilitates the expression of disgust, fear, anxiety, and adaptive avoidance behaviours. In this selective review, drawing primarily from rodent studies, the neurobiological mechanisms underlying the detection and assessment of infection status and their relations to mate choice are briefly considered. Firstly, we offer a brief overview of the aspects of mate choice that are relevant to pathogen avoidance. Then, we specifically focus on the olfactory detection of and responses to conspecific cues of parasitic infection, followed by a brief overview of the neurobiological systems underlying the elicitation of disgust and the expression of avoidance of the pathogen threat. Throughout, we focus on current findings and provide suggestions for future directions and research.

A Scoping Review of Studies on Assistive Technology Interventions and Their Impact on Individuals with Autism Spectrum Disorder in Arab Countries

The rising prevalence of autism spectrum disorder (ASD) in Arab countries necessitates evidence-based interventions. Assistive technology (AT) presents a promising approach. However, data on the pervasiveness of AT use and its effectiveness for individuals with ASD, specifically within Arab countries, remain scarce.

OBJECTIVE

To review the current literature on the AT interventions and outcomes reported for individuals with ASD in Arab countries.

METHODS

A scoping review adhering to PRISMA guidelines was undertaken to explore the utilization of AT, segmented into three categories: low-technology (low-tech), mid-technology (mid-tech), and high-technology (high-tech) devices.

RESULTS

Twelve studies had a pooled sample of 1547 participants, primarily male school-aged children with ASD. The AT applications evaluated ranged from low-tech visual schedules and support to high-tech virtual reality systems. Studies have reported the potential benefits of AT in improving communication, social, academic, adaptive, and functional abilities; however, comparative evidence between AT interventions is limited. The identified barriers to the adoption of AT included caregiver uncertainty about the use of AT and a lack of awareness of AT among professionals and the Arab community in general.

CONCLUSION

Available studies suggest that the adoption of AT can enhance the skills of individuals with ASD in Arab countries. However, more rigorous studies across diverse demographic groups and Arab national regions are needed to strengthen the evidence base and provide appropriate recommendations.

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.

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.