Adolescent exposure to bisphenol-a antagonizes androgen regulation of social behavior in male mice.

Social behavior is sexually dimorphic, which is regulated by gonadal hormones in the brain. Our recent study found that exposure to low doses of bisphenol-A (BPA) during adolescence, permanently alters social behavior in adult male mice, but the underlying mechanisms remain unclear. Using adolescent gonadectomy (GDX) male mice with testosterone propionate (TP, 0.5 mg/kg) supplement (TP-GDX), this study showed that BPA antagonized promoting effects of TP on social interaction, sexual behavior, and aggression in GDX mice. BPA eliminated the reversal effects of TP on GDX-induced decrease in the number of immunoreactive to arginine vasopressin (AVP-ir) neurons in the medial amygdala (MeA) and the levels of AVP receptor 1a (V1aR) in the MeA and the nucleus accumbens (NAc). In addition, BPA removed down-regulation in the levels of dopamine (DA) transporter (DAT) and DA receptor 1 (DR1) in the NAc of TP-GDX mice. BPA exposure reduced testosterone (T) levels in the brain and serum and the expression of androgen receptor (AR) protein in the amygdala and striatum of sham-operated and TP-GDX males. These results suggest that adolescent exposure to BPA inhibits regulation of androgen in AVP and DA systems of the brain regions associated with social behavior, and thus alters social behaviors of adult male mice.

Correlations of brain structure with the social behavior of 15q11-13 duplication mice, an animal model of autism.

Duplication of chromosome 15q11-13 has been reported to be one of the most frequent cytogenetic copy number variations in autism spectrum disorder (ASD), and a mouse model of paternal 15q11-13 duplication was generated, termed 15q dup mice. While previous studies have replicated some of the behavioral and brain structural phenotypes of ASD separately, the relationship between brain structure and behavior has rarely been examined. In this study, we performed behavioral experiments related to anxiety and social behaviors and magnetic resonance imaging (MRI) using the same set of 15q dup and wild-type mice. 15q dup mice showed increased anxiety and a tendency toward alterations in social behaviors, as reported previously, as well as variability in terms of sociability. MRI analysis revealed that a lower sociability index was correlated with a smaller gray matter volume in the right medial entorhinal cortex. These results may help to understand how variability in behavioral phenotypes of ASD arises even in individuals with the same genetic background and to determine the individual differences in neurodevelopmental trajectory correlated with specific brain structures that underlie these phenotypes.

Distinct subcircuits within the mesolimbic dopamine system encode the salience and valence of social stimuli.

The mesolimbic dopamine (DA) system (MDS) is the canonical "reward" pathway that has been studied extensively in the context of the rewarding properties of sex, food, and drugs of abuse. In contrast, very little is known about the role of the MDS in the processing of the rewarding and aversive properties of social stimuli. Social interactions can be characterized by their salience (i.e., importance) and their rewarding or aversive properties (i.e., valence). Here, we test the novel hypothesis that projections from the medial ventral tegmental area (VTA) to the nucleus accumbens (NAc) core codes for the salience of social stimuli through the phasic release of DA in response to both rewarding and aversive social stimuli. In contrast, we hypothesize that projections from the lateral VTA to the NAc shell codes for the rewarding properties of social stimuli by increasing the tonic release of DA and the aversive properties of social stimuli by reducing the tonic release of DA. Using DA amperometry, which monitors DA signaling with a high degree of temporal and anatomical resolution, we measured DA signaling in the NAc core or shell while rewarding and aversive social interactions were taking place. These findings, as well as additional anatomical and functional studies, provide strong support for the proposed neural circuitry underlying the response of the MDS to social stimuli. Together, these data provide a novel conceptualization of how the functional and anatomical heterogeneity within the MDS detect and distinguish between social salience, social reward, and social aversion. Significance Statement: Social interactions of both positive and negative valence are highly salient stimuli that profoundly impact social behavior and social relationships. Although DA projections from the VTA to the NAc are involved in reward and aversion little is known about their role in the saliency and valence of social stimuli. Here, we report that DA projections from the mVTA to the NAc core signal the salience of social stimuli, whereas projections from the lVTA to the NAc shell signal valence of social stimuli. This work extends our current understanding of the role of DA in the MDS by characterizing its subcircuit connectivity and associated function in the processing of rewarding and aversive social stimuli.

The lateral habenula integrates age and experience to promote social transitions in developing rats.

Early caregiving adversity (ECA) is associated with social behavior deficits and later development of psychopathology. However, the infant neural substrates of ECA are poorly understood. The lateral habenula (LHb), a highly conserved brain region with consistent links to adult psychopathology, is understudied in development, when the brain is most vulnerable to environmental impacts. Here, we describe the structural and functional ontogeny of the LHb and its behavioral role in infant and juvenile rat pups. We show that the LHb promotes a developmental transition in social approach behavior under threat as typically reared infants mature. By contrast, we show that ECA disrupts habenular ontogeny, including volume, protein expression, firing properties, and corticohabenular connectivity. Furthermore, inhibiting a specific corticohabenular projection rescues infant social approach deficits following ECA. Together, these results identify immediate biomarkers of ECA in the LHb and highlight this region as a site of early social processing and behavior control.

Unveiling Unexpected Selfless Collectivism: Exploring Variances in Moral Beliefs Across Cultural Values.

Purpose: The impact of moral beliefs on individuals' moral judgments, particularly within the framework of contrasting cultural values such as collectivism and individualism, continues to be a subject of interest. This research delves into whether individuals with distinct values display differences in moral beliefs, with a specific focus on selflessness. Methods: Through experiment 1 and 2, we scrutinize the moral judgments of individuals with diverse values concerning pro-social behaviors driven by selflessness and in-group favoritism. Experiment 3 investigates the underlying mechanisms by examining reward expectations. Results: The findings from experiments 1 and 2 indicate that collectivists exhibit significantly higher moral judgment levels for selfless pro-social behaviors compared to individualists, highlighting a disparity in moral beliefs between the two value systems. Experimental 2 also found that collectivists' moral judgments rose and fell as rescuers' selflessness increased or decreased. However, individualist moral judgment did not change significantly with behavioral selflessness. The results reveal that collectivists hold higher reward expectations for selfless behavior, which contributes to their heightened moral judgment of selfless behavior. Conclusion: While it may be assumed that collectivists' moral beliefs would be dominated by in-group preferences, aligning with the conceptual in-group preference of collectivism, this study unexpectedly found evidence of collectivists' pursuit of selflessness in their moral beliefs. These findings offer initial evidence of distinct patterns of moral beliefs associated with collectivism and individualism, shedding light on potential reasons that lead collectivists to possess stronger moral beliefs about selflessness.

The core tendencies underlying prosocial behavior: Testing a person-situation framework.

OBJECTIVE AND BACKGROUND: According to a recently proposed theoretical framework, different personality traits should explain pro-social behavior in different situations. We empirically tested the key proposition of this framework that each of four "core tendencies" (i.e., the shared variance of related traits) specifically predicts pro-social behavior in the presence of a different situational affordance. METHODS: We used a large-scale dataset (N = 2479) including measures of various personality traits and six incentivized economic games assessing pro-social behavior in different social situations. Using bifactor modeling, we extracted four latent core tendencies and tested their predictive validity for pro-social behavior. RESULTS: We found mixed support for the theoretically derived, preregistered hypotheses. The core tendency of beliefs about others' pro-sociality predicted pro-social behavior in both games involving dependence under uncertainty, as expected. Unconditional concern for others' welfare predicted pro-social behavior in only one of two games providing a possibility for exploitation. For conditional concern for others' welfare and self-regulation, in turn, evidence relating them to pro-social behavior in the presence of a possibility for reciprocity and temporal conflict was relatively weak. CONCLUSION: Different features of social situations may activate different personality traits to influence pro-social behavior, but more research is needed to fully understand these person-situation interactions.

Investigating the role of adversity and benevolence beliefs in predicting prosociality.

BACKGROUND: Does experiencing adversity engender kindness, and if so, for whom? Two studies tested the hypothesis that adversity predicts increased pro-social outcomes, and that this relationship is strongest for individuals who view others as good and trustworthy, or benevolent. METHOD: In Study 1, a cross-sectional survey design was utilized, and in Study 2 a longitudinal survey was conducted. RESULTS: In Study 1 (N = 359), the number of lifetime adverse life events was associated with increased volunteering, empathic concern, and self-reported altruism. The association of adversity and altruism was stronger for those with greater benevolence beliefs. In Study 2 (N = 1157), benevolence beliefs were assessed, and in subsequent years, adverse life events were reported. The number of past-year adverse life events predicted more volunteering and charitable involvement, but only among people with high benevolence beliefs. CONCLUSION: Exposure to adversity may be associated with increased pro-social behavior among those with higher benevolence beliefs. In part, this could be due to benevolence beliefs increasing the expectation that one's efforts will be appreciated and reciprocated.

Gender-based violence and harassment at work and health and occupational outcomes. A systematic review of prospective studies.

BACKGROUND: Many people experience forms of gender-based violence and harassment (GBVH) in the context of their work. This includes a wide range of experiences, from subtle expressions of hostility to physical assault, that can also be of a sexual nature (e.g., sexual harassment or assault). This systematic review aimed to summarize findings about the prospective associations of work-related GBVH with people's health and occupational situation. METHODS: We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Scopus, Web of Science, MEDLINE and PsycINFO were searched for prospective studies in English from 1990 to May 24, 2023. Studies were included if they concerned a working population, exposure to any form of GBVH in the work context, and a health outcome or manifest occupational outcome. Quality was assessed with a modified version of the Cochrane 'Tool to Assess Risk of Bias in Cohort Studies', and studies assessed as low quality were excluded from the narrative synthesis. For the narrative synthesis, we grouped the results by similar exposures and outcomes and reported the strength and statistical significance of the associations. RESULTS: Of the 1 937 screened records, 29 studies were included in the narrative synthesis. Studies were mainly conducted in the USA and northern Europe and investigated exposure to sexual violence or harassment (SVH). Only two included studies investigated non-sexual kinds of GBVH. Consistently, studies showed associations of work-related SVH with poor mental health and there were indications of an association with hazardous substance use. There was no consistent evidence for an association of SVH with subsequent sickness absence, and there were too few studies concerning physical health and occupational outcomes to synthesize the results. CONCLUSIONS: There is consistent evidence of work-related SVH as a risk factor for subsequent poor mental health. There is no indication that the health consequences of SVH differ between women and men, although women are more often affected. There is a need for conceptual consistency, the consideration of non-sexual behaviors and prospective studies that test clear hypotheses about the temporal sequence of events.

Variation in season length and development time is sufficient to drive the emergence and coexistence of social and solitary behavioral strategies.

Season length and its associated variables can influence the expression of social behaviors, including the occurrence of eusociality in insects. Eusociality can vary widely across environmental gradients, both within and between different species. Numerous theoretical models have been developed to examine the life history traits that underlie the emergence and maintenance of eusociality, yet the impact of seasonality on this process is largely uncharacterized. Here, we present a theoretical model that incorporates season length and offspring development time into a single, individual-focused model to examine how these factors can shape the costs and benefits of social living. We find that longer season lengths and faster brood development times are sufficient to favor the emergence and maintenance of a social strategy, while shorter seasons favor a solitary one. We also identify a range of season lengths where social and solitary strategies can coexist. Moreover, our theoretical predictions are well-matched to the natural history and behavior of two flexibly-eusocial bee species, suggesting our model can make realistic predictions about the evolution of different social strategies. Broadly, this work reveals the crucial role that environmental conditions can have in shaping social behavior and its evolution and underscores the need for further models that explicitly incorporate such variation to study evolutionary trajectories of eusociality.

Beware of Strangers: Dogs' Empathetic Response to Unknown Humans.

Empathy is a complex cognitive ability that has been studied in many social animals, including dogs. Previous studies have found that dogs would rescue their distressed owner more quickly than a calm owner and that dogs respond physiologically and behaviorally to the sound of crying strangers. However, no studies have explored the empathetic and emotional contagion capabilities of dogs towards strangers in rescue paradigms. In the present study, a stranger was placed behind a clear door and was told to cry (distress) or hum (neutral). The dogs' door opening, stress behaviors, tone of approach, and physiological responses were measured. Dogs did not open more frequently or more quickly for the stranger in the distressed condition compared to the neutral condition. Additionally, there was no significant difference between the behavioral or physiological indicators of stress across conditions. It was also found that non-openers were reported by owners to have more fear and, in the empathy test, were more aggressive and fearful in their tone of approach. These results suggest that dogs may be less likely to exhibit empathy-like behaviors to unknown humans in an unfamiliar environment and that owners may be necessary to moderate a dog's stress to show empathetic behaviors.

Short- and Long-Term Neurobehavioral Effects of Developmental Exposure to Valproic Acid in Zebrafish.

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by impairments in social interaction and communication, anxiety, hyperactivity, and interest restricted to specific subjects. In addition to the genetic factors, multiple environmental factors have been related to the development of ASD. Animal models can serve as crucial tools for understanding the complexity of ASD. In this study, a chemical model of ASD has been developed in zebrafish by exposing embryos to valproic acid (VPA) from 4 to 48 h post-fertilization, rearing them to the adult stage in fish water. For the first time, an integrative approach combining behavioral analysis and neurotransmitters profile has been used for determining the effects of early-life exposure to VPA both in the larval and adult stages. Larvae from VPA-treated embryos showed hyperactivity and decreased visual and vibrational escape responses, as well as an altered neurotransmitters profile, with increased glutamate and decreased acetylcholine and norepinephrine levels. Adults from VPA-treated embryos exhibited impaired social behavior characterized by larger shoal sizes and a decreased interest for their conspecifics. A neurotransmitter analysis revealed a significant decrease in dopamine and GABA levels in the brain. These results support the potential predictive validity of this model for ASD research.

miRNA-mediated inhibition of an actomyosin network in hippocampal pyramidal neurons restricts sociability in adult male mice.

Social deficits are frequently observed in patients suffering from neurodevelopmental disorders, but the molecular mechanisms regulating sociability are still poorly understood. We recently reported that the loss of the microRNA (miRNA) cluster miR-379-410 leads to hypersocial behavior and anxiety in mice. Here, we show that ablating miR-379-410 in excitatory neurons of the postnatal mouse hippocampus recapitulates hypersociability, but not anxiety. At the cellular level, miR-379-410 loss in excitatory neurons leads to larger dendritic spines, increased excitatory synaptic transmission, and upregulation of an actomyosin gene network. Re-expression of three cluster miRNAs, as well as pharmacological inhibition of the actomyosin activator ROCK, is sufficient to reinstate normal sociability in miR-379-410 knockout mice. Several actomyosin genes and miR-379-410 family members are reciprocally dysregulated in isogenic human induced pluripotent stem cell (iPSC)-derived neurons harboring a deletion present in patients with Williams-Beuren syndrome, characterized by hypersocial behavior. Together, our results show an miRNA-actomyosin pathway involved in social behavior regulation.

Threat-induced prosocial behavior: enhanced exogenous attention to protect others from harm.

As social animals, humans tend to voluntarily engage in pro-social behavior to prevent harm to others. However, to what extent prosocial behavior can be reflected at the level of less voluntary cognitive processes remains unclear. Here, we examined how threat to others modulates exogenous attention. Fifty-four participants performed an exogenous spatial cueing task where the participant's performance determined whether electric shocks would be delivered either to themselves or to their anonymous co-participant. Threat of shock to the co-participant elicited orienting and reorienting responses that were faster than in the safe condition and did not differ from performance when participants avoided shocks to themselves. This attentional improvement was not due to speed-accuracy trade off and was associated with arousal, i.e., increased pupil dilation in both threat conditions. Together, these findings suggest that pro-social behavior triggers automatic attentional processes which may be relevant for providing immediate help without relying on reflexive processes.

Adaptive group behavior of Fragile X mice in unfamiliar environments.

Fragile X Syndrome (FXS) stands out as a prominent cause of inherited intellectual disability and a prevalent disorder closely linked to autism. FXS is characterized by substantial alterations in social behavior, encompassing social withdrawal, avoidance of eye contact, heightened social anxiety, increased arousal levels, language deficits, and challenges in regulating emotions. Conventional behavioral assessments primarily focus on short-term interactions within controlled settings. In this study, we conducted a comprehensive examination of the adaptive group behavior of Fmr1 KO male mice over a three-day period, without introducing experimental interventions or task-based evaluations. The data unveiled intricate behavioral anomalies, with the most significant changes manifesting during the initial adaptation to unfamiliar environments. Notably, certain behaviors exhibited a gradual return to typical patterns over time. This dynamic Fmr1 KO phenotype exhibited heightened activity, featuring increased exploration, amplified social interest, and an unconventional approach to social interactions characterized by a higher frequency of shorter engagements. These findings contribute to the growing understanding of social behavior in individuals with FXS and underscore the significance of comprehending their adaptive responses in various environmental contexts.

Neuroimaging and behavioral evidence of sex-specific effects of oxytocin on human sociality.

Although the social role of oxytocin came to light due to sex-specific interactions such as mother-offspring bonding, current understanding of sex differences in the effects of oxytocin on human sociality is limited because of the predominance of all-male samples. With the increasing inclusion of females in intranasal oxytocin research, it is now possible to explore such patterns. Neuroimaging studies reveal relatively consistent sex-differential effects of oxytocin on the activation of brain regions associated with processing social stimuli - particularly the amygdala. Findings from behavioral research are varied but suggest that oxytocin more often facilitates social cognition and positive social interactions in males, with context-dependent effects in each sex. We discuss potential biological and psychological mechanisms underlying the reported sex differences, and conclude with considerations for future research and clinical applications of oxytocin.

Gut microbiota influences onset of foraging-related behavior but not physiological hallmarks of division of labor in honeybees.

Gut microbes can impact cognition and behavior, but whether they regulate the division of labor in animal societies is unknown. We addressed this question using honeybees since they exhibit division of labor between nurses and foragers and because their gut microbiota can be manipulated. Using automated behavioral tracking and controlling for co-housing effects, we show that gut microbes influence the age at which bees start expressing foraging-like behaviors in the laboratory but have no effects on the time spent in a foraging arena and number of foraging trips. Moreover, the gut microbiota did not influence hallmarks of behavioral maturation such as body weight, cuticular hydrocarbon profile, hypopharyngeal gland size, gene expression, and the proportion of bees maturing into foragers. Overall, this study shows that the honeybee gut microbiota plays a role in controlling the onset of foraging-related behavior without permanent consequences on colony-level division of labor and several physiological hallmarks of behavioral maturation. IMPORTANCE: The honeybee is emerging as a model system for studying gut microbiota-host interactions. Previous studies reported gut microbiota effects on multiple worker bee phenotypes, all of which change during behavioral maturation-the transition from nursing to foraging. We tested whether the documented effects may stem from an effect of the microbiota on behavioral maturation. The gut microbiota only subtly affected maturation: it accelerated the onset of foraging without affecting the overall proportion of foragers or their average output. We also found no effect of the microbiota on host weight, cuticular hydrocarbon (CHC) profile, hypopharyngeal gland size, and the expression of behavioral maturation-related genes. These results are inconsistent with previous studies reporting effects of the gut microbiota on bee weight and CHC profile. Our experiments revealed that co-housed bees tend to converge in behavior and physiology, suggesting that spurious associations may emerge when rearing environments are not replicated sufficiently or accounted for analytically.

Associations between teacher-parent relationships and preschool children's social behavior problems-the chain mediating roles of work-family conflict and parenting self-efficacy.

In the Chinese cultural context, the collaborative interaction characteristics among three key entities - families, kindergartens, and communities - and the mechanisms of their correlation with preschool children's social behavior problems have not been fully understood yet. Based on ecological systems Theory and social support theory, this study aimed to examine the correlation between parent-teacher relationships and preschool children's social behavior problems in Chinese kindergartens, as well as the mediating role of parents' work-family conflict and parenting self-efficacy. Structural equation modeling was used to test the research hypotheses based on a questionnaire survey of 1,784 parents of preschool children. The main findings of this study are as follows: (1) Parents' perceived positive parent-teacher relationships are negatively correlated with preschool children's social problems. (2) Parents' work-family conflict and parenting self-efficacy mediate the relationship between parent-teacher relationships and preschool children's social behavior problems; (3) Parents' work-family conflict and parenting self-efficacy play a chain mediating role in the influence of the parent-teacher relationship on preschool children's social behavior problems. Taken together, the results collectively further elucidate the correlation between parent-teacher relationships and preschool children's social behavior problems, while also discussing other relevant factors pertaining to children's social behavior problems. Theoretically, this study expands the understanding of how external environmental resources interact with home and family education. Practically, this research indicates that governments, early childhood education institutions, and workplaces need to strengthen their support for family education of preschool children. The findings contribute to promoting a multi-faceted co-operation aimed at enhancing the quality of early childhood education and fostering the social adaptability and holistic development of preschool children.

The effect of group size on sleep in a neotropical bat, Artibeus jamaicensis.

Sleep is associated with many costs, but is also important to survival, with a lack of sleep impairing cognitive function and increasing mortality. Sleeping in groups could alleviate sleep-associated costs, or could introduce new costs if social sleeping disrupts sleep. Working with the Jamaican fruit bat (Artibeus jamaicensis), we aimed to: (1) describe sleep architecture, (2) assess how sleeping in groups affects sleep, and (3) quantify total sleep time and identify rapid eye movement (REM) sleep using behavioral indicators that complement physiological evidence of sleep. Twenty-five adult bats were captured in Panama and recorded sleeping in an artificial roost enclosure. Three bats were fitted with an electromyograph and accelerometer and video recorded sleeping alone in controlled laboratory settings. The remaining 22 bats were assigned to differing social configurations (alone, dyad, triad, and tetrad) and video recorded sleeping in an outdoor flight cage. We found that sleep was highly variable among individuals (ranging from 2 h 53 min to 9 h 39 min over a 12-h period). Although we did not detect statistically significant effects and our sample size was limited, preliminary trends suggest that male bats may sleep longer than females, and individuals sleeping in groups may sleep longer than individuals sleeping alone. We also found a high correspondence between total sleep time quantified visually and quantified using actigraphy (with a 2-min immobility threshold) and identified physiological correlates of behaviorally-defined REM. These results serve as a starting point for future work on the ecology and evolution of sleep in bats and other wild mammals.

Dormir está asociado con muchos costos, pero también es importante para la supervivencia, ya que la falta de sueño perjudica la función cognitiva y aumenta la mortalidad. Dormir en grupos podría disminuir los costos asociados con el sueño o podría introducir nuevos costos si este descanso grupal interrumpe el sueño. Trabajando con el murciélago frugívoro jamaicano (A. jamaicensis), nos propusimos: (1) describir la arquitectura del sueño, (2) evaluar cómo dormir en grupos afecta el sueño y (3) cuantificar el tiempo total de sueño e identificar el sueño REM empleando indicadores de comportamiento que complementen la evidencia fisiológica del sueño. Se capturaron 25 murciélagos adultos en Panamá y se les grabó durmiendo en un recinto artificial de descanso. A tres murciélagos se les equipó con un electromiógrafo y un acelerómetro y se les grabó en video durmiendo solos en entornos de laboratorio controlados. Los 22 murciélagos restantes fueron asignados a diferentes configuraciones sociales (solo, díada, tríada, tétrada) y se grabaron en video durmiendo en una jaula de vuelo al aire libre. El sueño fue muy variable entre individuos (desde 2 h 53 min hasta 9 h 39 min durante un período de 12 h). Aunque no detectamos efectos estadísticamente significativos, y nuestro tamaño muestral fue limitado, las tendencias preliminares sugieren que los murciélagos macho pueden dormir más que las hembras, y que los individuos que duermen en grupos pueden dormir más que los individuos que duermen solos. Encontramos una alta correspondencia entre el tiempo total de sueño cuantificado visualmente y cuantificado mediante actigrafía (con un umbral de inmovilidad de 2 minutos) e identificamos correlaciones fisiológicas de lo que definimos como REM en términos de comportamiento. Estos resultados sirven como punto de partida para futuros estudios sobre la ecología y la evolución del sueño en murciélagos y otros mamíferos salvajes.

Peptides and primate personality: Central and peripheral oxytocin and vasopressin levels and social behavior in two baboon species (Papio hamadryas and Papio anubis).

The neurohormones oxytocin (OT) and arginine vasopressin (AVP) are involved in social behaviors and psychiatric conditions. However, more research on nonhuman primates with complex social behaviors is needed. We studied two closely-related primate species with divergent social and mating systems; hamadryas baboons (Papio hamadryas, n=38 individuals) and anubis baboons (Papio anubis, n=46). We measured OT in cerebrospinal fluid (CSF, n=75), plasma (n=81) and urine (n=77), and AVP in CSF (n=45), and we collected over 250 hours of focal behavioral observations. Using Bayesian multivariate models, we found no clear species difference in hormone levels; the strongest support was for hamadryas having higher CSF OT levels than anubis (posterior probability [PP] for females = 0.75, males = 0.84). Looking at nine specific behaviors, OT was associated with affiliative behaviors (approach, proximity, grooming, PP ∼ 0.85 - 1.00), albeit inconsistently across sources of measurement (CSF, plasma, and urine, which were uncorrelated with each other). Most behaviors had low repeatability (R ∼ 0 - 0.2), i.e. they did not exhibit stable between-individual differences (or "personality"), and different behaviors did not neatly coalesce into higher-order factors (or "behavioral syndromes"), which cautions against the use of aggregate behavioral measures and highlights the need to establish stable behavioral profiles when testing associations with baseline hormone levels. In sum, we found some associations between peptides and social behavior, but also many null results, OT levels from different sources were uncorrelated, and our behavioral measures did not indicate clear individual differences in sociability.

rTMS Ameliorates time-varying depression and social behaviors in stimulated space complex environment associated with VEGF signaling.

Studies have indicated that medium- to long-duration spaceflight may adversely affect astronauts' emotional and social functioning. Emotion modulation can significantly impact astronauts' well-being, performance, mission safety and success. However, with the increase in flight time, the potential alterations in emotional and social performance during spaceflight and their underlying mechanisms remain to be investigated, and targeted therapeutic and preventive interventions have yet to be identified. We evaluated the changes of emotional and social functions in mice with the extension of the time in simulated space complex environment (SSCE), and simultaneously monitored changes in brain tissue of vascular endothelial growth factor (VEGF), matrix metalloproteinase-9 (MMP-9), and inflammation-related factors. Furthermore, we assessed the regulatory role of repetitive transcranial magnetic stimulation (rTMS) in mood and socialization with the extension of the time in SSCE, as well as examining alterations of VEGF signaling in the medial prefrontal cortex (mPFC). Our findings revealed that mice exposed to SSCE for 7 days exhibited depressive-like behaviors, with these changes persisting throughout SSCE period. In addition, 14 days of rTMS treatment significantly ameliorated SSCE-induced emotional and social dysfunction, potentially through modulation of the level of VEGF signaling in mPFC. These results indicates that emotional and social disorders increase with the extension of SSCE time, and rTMS can improve the performance, which may be related to VEGF signaling. This study offers insights into potential pattern of change over time for mental health issues in astronauts. Further analysis revealed that rTMS modulates emotional and social dysfunction during SSCE exposure, with its mechanism potentially being associated with VEGF signaling.