Sex Differences In Social Interaction Research Articles

Oxytocin system driven by experiences modifies social recognition and neuron morphology in female BALB/c mice

The oxytocin (OT) system, affected by life experiences, modulates neuron morphology in a sex-specific manner, leading to sex differences in social interactions. To date, few studies have focused on the OT system and social interactions of female mice. In this study, we used maternal deprivation (MD) and its possible treatment, environmental enrichment (EE), to affect social recognition in female BALB/c mice. We checked neuron morphology, synaptic connections, oxytocinergic (OTergic) neurons in the hypothalamus paraventricular nucleus (PVH), and OT receptor (OTR) in the basolateral amygdala (BLA) and layer II/III of the prelimbic cortex (PL). Our results showed that MD induced social recognition impairments, increased OTR levels in the BLA, and, meanwhile, reduced OTergic neurons in the magnocellular region of the PVH (mPVH). Decreased Nissl bodies, increased cell nuclei, and increased dendrites of projection neurons paralleled the increased OTR levels in the BLA of MD mice. EE restored MD-induced the impairments of novel object recognition and sociability; this effect paralleled a decrease in cell density in the PL and an increase in OTergic neurons in the parvocellular regions of the PVH and synaptic connections in the BLA and layer II/III of the PL. Our findings indicate that early life stress such as MD impairs social recognition, and meanwhile, remodels neuron morphology region-specifically in the female brain, apparently in the BLA but slightly in the PL; and EE could partially restore the deficits induced by MD. The results provide new insights into sex differences in the prevalence of psychological development disorders.

Sex differences in the Role of Basolateral Amygdala Projections to the Bed Nucleus of the Stria Terminalis in Anticipatory Anxiety

Sustained anxiety in the absence of a threat can lead to pathological manifestations like post traumatic stress disorder (PTSD) and anxiety disorders. Recent data suggest that the bed nucleus of the stria terminalis (BST) is implicated in the shift from a phasic to sustained anxiety state, but the specific mechanisms by which this occurs remains unknown. We developed a model for sustained fear conditioning to a long duration cue (8 min) paired with intermittent foot shocks in order to better understand the neurocircuitry of anticipatory anxiety. Sex differences in the prevalence of anxiety disorders exist and a secondary goal of this work was to examine if sex differences exist in anticipatory anxiety during prolonged cues and the circuitry that contributes to this behavior. One of the major inputs to the BST activated during sustained fear learning is the basolateral amygdala (BLA), which also differs in activity between sexes. To determine a role for BLA projecting BST neurons (BLA-BST) in this sustained anxiety paradigm, we examined DREADD-induced suppression of the BLA-BST pathway during prolonged cued fear conditioning in both male and female rats. In males, inhibition of BLA-BST during extinction hastened the extinction of freezing compared to male controls, but had no effect on freezing behavior in females. Inhibition of BLA-BST did not alter exploration of the central area in the open field task, a test of general anxiety-like behavior, in either sex. Since the BLA-BST pathway also mediates social anxiety-like behavior in humans and animals, we assessed potential sex differences in social interaction (SI) following suppression of this pathway. Inhibition of the BLA-BST pathway increased SI time and reduced the latency to interact in male, but not female rats. Together, these results suggest that the BLA-BST projection does not modulate generalized anxiety-like behavior, but is specific to anticipatory anxiety induced by prolonged cued fear or an unpredictable social environment and differs between sexes. To examine potential sex differences in BLA-BST neurons, we implemented in vivo and in vitro electrophysiological approaches to determine the activity of these neurons. While spontaneous general BLA neuronal activity was augmented in females compared to males, sex differences were noted in the activity of BLA-BST projections. In males, the BLA-BST projection neurons were more active and excitable which coincided with a smaller after hyperpolarization (AHP) amplitude compared to other non-BST-projecting BLA neurons whereas in females, BLA-BST neurons were less excitable and had larger AHP amplitudes compared to non-BST-projecting BLA neurons. These physiological data support our behavioral experiment findings in which increased activity of BLA-BST neurons mediates anticipatory anxiety-like behavior in males, but not females. These novel findings suggest BLA-BST neurons contribute to anticipatory anxiety in male rats, but not females. Moreover, these sex differences in neurocircuitry may explain the sex disparity in anxiety disorders.

Sex Differences in Social Participation of High School Students with Autism Spectrum Disorder.

There is lack of consensus in the literature regarding sex differences in social outcomes for individuals on the autism spectrum. Furthermore, little research has focused on the social experiences of high school students with autism spectrum disorder (ASD) during the school day. Using a large racially/ethnically diverse sample of high school students with ASD receiving special education services (n = 547; 76 females, 471 males), we examined sex differences in social interactions of youth both during and after school. We also tested for sex differences in background and phenotypic characteristics including autism severity, IQ, adaptive behavior, and mental health. Results indicated few statistically significant differences between males and females in social interactions and phenotypic characteristics (including raw scores of autism symptom severity). However, analysis of standardized scores of autism symptoms suggested that symptom scores for females with ASD diverged more from same-sex peers in the normed sample than scores of males with ASD. Lack of sex difference in social participation for youth with ASD in this study stands in contrast to patterns of sex differences in the general population. Findings suggest that few differences between males and females with ASD, both in social participation and autism symptom severity, might result in females with ASD being more dissimilar to their same-sex peers than males with ASD. Implications of findings for understanding sex differences in ASD across the life course are discussed. LAY SUMMARY: The present study examined sex differences in social participation in a large, diverse sample of high school students with autism spectrum disorder (ASD). Males and females were very similar in their social interactions both at school and outside of school, based on reports by teachers and parents. Level of autism symptoms was also similar for males and females. However, standardized scores of autism symptoms, which take into account age and sex specific norms, suggested that females with ASD may have behaviors that are more divergent from their same-sex peers than males with ASD.

Viral-mediated Zif268 expression in the prefrontal cortex protects against gonadectomy-induced working memory, long-term memory, and social interaction deficits in male rats

In humans, some males experience reductions in testosterone levels, as a natural consequence of aging or in the clinical condition termed hypogonadism, which are associated with impaired cognitive performance and mood disorder(s). Some of these behavioral deficits can be reversed by testosterone treatment. Our previous work in rats reported that sex differences in the expression of the transcription factor Zif268, a downstream target of testosterone, within the medial prefrontal cortex (mPFC) mediates sex differences in social interaction. In the present study, we aimed to examine the effects of gonadectomy (GNX) in male rats on mPFC Zif268 expression, mood and cognitive behaviors. We also examined whether reinstitution of Zif268 in GNX rats will correct some of the behavioral deficits observed following GNX. Our results show that GNX induced a downregulation of Zif268 protein in the mPFC, which was concomitant with impaired memory in the y-maze and spontaneous object recognition test, reduced social interaction time, and depression-like behaviors in the forced swim test. Reinstitution of mPFC Zif268, using a novel adeno-associated-viral (AAV) construct, abrogated GNX-induced working memory and long-term memory impairments, and reductions in social interaction time, but not GNX-induced depression-like behaviors. These findings suggest that mPFC Zif268 exerts beneficial effects on memory and social interaction, and could be a potential target for novel treatments for behavioral impairments observed in hypogonadal and aged men with declining levels of gonadal hormones.

Sex Differences in Object Manipulation in Wild Immature Chimpanzees (Pan troglodytes schweinfurthii) and Bonobos (Pan paniscus): Preparation for Tool Use?

Sex differences in immatures predict behavioural differences in adulthood in many mammal species. Because most studies have focused on sex differences in social interactions, little is known about possible sex differences in ‘preparation’ for adult life with regards to tool use skills. We investigated sex and age differences in object manipulation in immature apes. Chimpanzees use a variety of tools across numerous contexts, whereas bonobos use few tools and none in foraging. In both species, a female bias in adult tool use has been reported. We studied object manipulation in immature chimpanzees at Kalinzu (Uganda) and bonobos at Wamba (Democratic Republic of Congo). We tested predictions of the ‘preparation for tool use’ hypothesis. We confirmed that chimpanzees showed higher rates and more diverse types of object manipulation than bonobos. Against expectation, male chimpanzees showed higher object manipulation rates than females, whereas in bonobos no sex difference was found. However, object manipulation by male chimpanzees was play-dominated, whereas manipulation types of female chimpanzees were more diverse (e.g., bite, break, carry). Manipulation by young immatures of both species was similarly dominated by play, but only in chimpanzees did it become more diverse with age. Moreover, in chimpanzees, object types became more tool-like (i.e., sticks) with age, further suggesting preparation for tool use in adulthood. The male bias in object manipulation in immature chimpanzees, along with the late onset of tool-like object manipulation, indicates that not all (early) object manipulation (i.e., object play) in immatures prepares for subsistence tool use. Instead, given the similarity with gender differences in human children, object play may also function in motor skill practice for male-specific behaviours (e.g., dominance displays). In conclusion, even though immature behaviours almost certainly reflect preparation for adult roles, more detailed future work is needed to disentangle possible functions of object manipulation during development.

Sex differences in social interaction of methamphetamine-treated rats

Our previous study showed that single injection of methamphetamine decreases social interaction (SI) in a dose-dependent manner that was further affected by stressful environment conditions. The aim of this study was to examine the effect of methamphetamine and its interaction with gonadal hormones on SI. Adult male and female rats were gonadectomized and assigned to testosterone-treated and oil-treated groups in male rats and estradiol-treated and oil-treated groups in female rats, respectively. Hormones were administered 30 min before each habituation in the open field. All four hormonal groups were further divided to control (without injection), saline (1 ml/kg saline injection), and methamphetamine (1 mg/kg) groups. Injections were applied 30 min before the SI test. The total duration and the total number of SI and nonsocial behavioral patterns were assessed. This study showed that an acute methamphetamine administration in a dose of 1 mg/kg decreased different types of SI in both sexes. In contrast, the same dose of methamphetamine increased locomotion and rearing behavior in male and female rats. The frequency and/or duration of SI (especially mutual sniffing and allogrooming) was lower in adult female rats relative to gonadectomized male rats, but locomotion was increased in female relative to male rats regardless of the presence or absence of gonadal hormones. In conclusion, this study is novel especially because it examines SI in both sexes in relation to the presence or absence of gonadal hormones.

Gestational Exposure to Low Dose Bisphenol A Alters Social Behavior in Juvenile Mice

Bisphenol A (BPA) is a man-made compound used to make polycarbonate plastics and epoxy resins; public health concerns have been fueled by findings that BPA exposure can reduce sex differences in brain and some behaviors. We asked if a low BPA dose, within the range measured in humans, ingested during pregnancy, would affect social behaviors in prepubertal mice. We noted sex differences in social interactions whereby females spent more time sitting side-by-side, while males engaged in more exploring and sitting alone. In addition BPA increased display of nose-to-nose contacts, play solicitations and approaches in both sexes. Interactions between sex and diet were found for self grooming, social interactions while sitting side-by-side and following the other mouse. In all these cases interactions were produced by differences between control and BPA females. We examined brains from embryos during late gestation to determine if gene expression differences might be correlated with some of the sexually dimorphic or BPA affected behaviors we observed. Because BPA treatments ended at birth we took the brains during embryogenesis to increase the probability of discovering BPA mediated effects. We also selected this embryonic age (E18.5) because it coincides with the onset of sexual differentiation of the brain. Interestingly, mRNA for the glutamate transporter, Slc1a1, was enhanced by exposure to BPA in female brains. Also we noted that BPA changed the expression of two of the three DNA methyltransferase genes, Dnmt1 and Dnmt3a. We propose that BPA affects DNA methylation of Sc1a1 during neural development. Sex differences in juvenile social interactions are affected by BPA and in particular this compound modifies behavior in females.

Sex Differences in Social Interaction in Rats: Role of the Immediate-Early Gene zif268

Given both the high prevalence of anxiety disorders in women and the fact that little is known about the mechanisms of gender differences in anxiety, our primary aim in this study was to investigate the neurobiological mechanisms underlying sex differences in social anxiety-like behavior in rats. Through the use of zif268 antisense oligodeoxynucleotides (zif ASO), we induced a temporary downregulation of zif268 expression in the medial prefrontal cortex of male and female rats and found that zif268 ASO male rats show more social anxiety-like behaviors when compared with control male rats in the social interaction test. In fact, zif268 ASO males displayed social anxiety-like behaviors, which were similar to control females, thus downregulation of zif268 expression in the mPFC of male rats eliminated sex differences previously found in the social anxiety-like behavior tests. Interestingly, zif268 ASO in female rats had no effect on their social interaction. Our novel findings have led us to ascertain that sexually dimorphic zif268 expression in the mPFC is a key molecular factor in mediating sex-specific anxiety-like behavior in the social interaction test.

Gender, networks, and adaptation among an inner-city population

In varied cultural frameworks men and women in old age have shown distinct differences in their ability to engage in social interaction. This article examines the sex differences in social interaction among 133 inner-city elderly living in SRO hotels. Contrary to earlier reports of inner-city elderly women, there was no evidence of pervasive isolation and longitudinal data indicated that SRO women had dynamic networks that allowed for the replacement of lost contacts with new ones. In comparing the sexes there were similarities in the various social network dimensions and the use of these networks to fulfill needs and cope with physical illness. Moreover, the similarities in life histories between the sexes would suggest that as women's life-styles in the general population come to approximate those of men, the social interactions of aging men and women may more closely resemble each other.

Self-Monitoring and Competence as Determinants of Sex Differences in Social Interaction

Abstract Male and female college students who had high or low task competence and high or low self-monitoring scores participated in two tasks; one male-oriented and one female-oriented. During the male-oriented task, high-competent males and low-competent females talked the most. During the female-oriented task, high-competent females and low-competent males talked the most. High self-monitors talked the most on the male-oriented task. On the female-oriented task, self-monitoring was not predictive of verbal activity.

Sex differences in social interaction between infant monkeys and their mothers.

Knowledge of the origin and development of sex differences in children is important in a dynamic formulation of social behavior. Although there is widespread belief that infant boys behave differently from girls, only scattered empirical evidence supports this view [1, 2]. The psychosocial theories of the origin of behavioral differences between the sexes emphasize cultural influences and psychological experience in terms of the parent’s, particularly the mother’s, attitudes and behaviors toward the child [3–5]. Animal behaviorists investigating sex differences have, on the other hand, emphasized unlearned or innate processes, particularly those effected and mediated by sex hormones [6, 7]. This gulf between developmental theories based on humans and on animal research appears to be large and resembles the old polarity between learned and innate determinants of behavior.KeywordsCombine GroupMale InfantRich EnvironmentDevelopmental TrendPrivation GroupThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.