Sex Differences In Behavior Research Articles

Sex difference feeding behaviour of NOD SCID mice in a pharmacological model of type 1 diabetes.

This study aimed to assess the sex differences in the feeding behaviour of non-obese diabetic severe combined immunodeficient (NOD SCID) mice in a pharmacological model of type 1 diabetes mellitus (T1Dm). In our study, we chose NOD SCID mice of both sexes and assessed their feeding behaviour, body weight, body fat and water content under identical experimental conditions and diets. After 1month of diabetes mellitus in mice in the experimental group, males and females did not show any increase in body weight, and they weighed significantly less than the control group. However, compared with the control group, in females with a background of T1Dm, there was a significant decrease in body fat. The amount of water consumed in the experimental groups was higher than that in the control groups. The amount of food consumed by males increased when they increased their water consumption, whereas food consumption in females decreased significantly with an increase in water consumption. Thus, we discovered sex differences in the feeding behaviour, body weight and body fat and water content in the pharmacological model of T1Dm after 1month in NOD SCID mice.

Understanding sex differences in physical activity behavior: The role of anxiety sensitivity

ProblemThere is a well-evidenced sex-disparity in physical activity (PA), such that females are significantly less active than males. Anxiety sensitivity, the fear of anxiety-related bodily sensations, is a cognitive-affective vulnerability associated with increased negative affect during PA and lower levels of PA. The current study examined anxiety sensitivity as a potential sex-specific, psychological factor related to sex differences in past-week PA behavior in daily cigarette smokers. MethodParticipants (n = 527; 53.3% female) completed an anonymous online survey on emotion and health. Anxiety sensitivity was assessed with the Anxiety Sensitivity Index-3. Past-week, self-reported PA minutes were measured across four intensities (e.g., walking, moderate, vigorous, and total PA) using the International Physical Activity Questionnaire-Short. Four zero-inflated negative binomial regression models were constructed to test the main and interactive effects of sex and anxiety sensitivity on PA outcomes. ResultsFemales reported significantly fewer past-week PA minutes relative to males across all domains. At higher levels of anxiety sensitivity, males reported significantly fewer total PA minutes; whereas, total PA levels in females were not dependent on anxiety sensitivity level. Additionally, females with elevated anxiety sensitivity reported significantly more past-week walking minutes relative to females with low anxiety sensitivity, whereas the opposite pattern was observed in males. ConclusionThis is the first study to our knowledge to examine sex differences in anxiety sensitivity and PA, at varying PA intensities, among smokers. These data have the potential to inform sex-specific models of anxiety, PA, and smoking.

Quasi Experimental Design in Scientific Psychology

For most of the history of scientific psychology, it has been accepted that experimental research, with its twin assets of random assignment and manipulation of the independent variable by the researcher, is the ideal method for psychological research. Some researchers believe this so strongly that they avoid studying important questions about human personality, sex differences in behaviour, and other subjects that do not lend themselves to experimental research. A few decades ago researchers in psychology were interested in applied psychology issues conducting research on how students learnt in school, how social factors influenced the behaviour of an individual, how to motivate factory workers to perform at a higher level etc. These research questions cannot be answered by lab experiments as one has to go to the field and the real life situation like the classroom etc., to find answers to the research issues mentioned above. Thus the quasi experimental research came into existence. Quasi-experimental research design can be more easily implemented in natural settings and one can make direct assessment of subjects, find out the effects of a specific treatment introduced by the researcher, and while doing so the researcher can also minimise the influence of extraneous variables. In this paper, the quasi experimental design is discussed with scientific significance.

Sex ratio of Western Bluebirds Sialia mexicana is mediated by phenology and clutch size.

Mothers may produce more of one sex to maximize their fitness if there are differences in the cost of producing each sex or there are differences in their relative reproductive value. Breeding date and clutch size are known to influence offspring sex ratios in birds through sex differences in dispersal, social behaviours, differential mortality, and available food resources. We tested if breeding date, clutch size and drought conditions influenced offspring sex ratios in a sexually size-monomorphic species, the Western Bluebird, by interrogating a 21-year dataset. After controlling for differential mortality, we found that hatch dates late in the breeding season were associated with the production of more females, suggesting that the value of producing males declines as the breeding season progresses. When clutch size was taken into account, small clutches yielded significantly more females late in the breeding season compared to the early and middle parts of the breeding season that produced significantly more males. Large clutches early in the season tended to produce more females, although this was not significant. Drought severity was not correlated with sex ratio adjustment. We propose and discuss several explanations for these patterns, including male offspring, but not female offspring, acting as helpers, increased female nestling provisioning late in the breeding season, differences in food abundance, and egg-laying order. Future work will help to uncover the mechanisms leading to these patterns. Identifying patterns and mechanisms of sex ratio skew from long-term datasets is important for informing predictions regarding life-history trade-offs in wildlife populations.

Comparison of joint degeneration and pain in male and female mice in DMM model of osteoarthritis

While the prevalence of radiographic and symptomatic osteoarthritis (OA) is higher in women, male mice are more frequently used in animal experiments to explore its pathogenesis or drug efficacy. In this study, we examined whether sexual dimorphism affects pain and joint degeneration in destabilization of the medial meniscus (DMM) mouse model. DMM or sham surgery was performed on the knee of male and female C57BL/6 mice. Joint damage was assessed by safranin O staining and scored using the Osteoarthritis Research Society International (OARSI) scoring system. Von Frey hair, incapacitance, and rotarod tests were conducted to measure joint pain. The analgesic effect of capsazepine (CPZ), a TRPV1 antagonist, was compared between male and female mice. Histology and OARSI scoring analysis showed that cartilage degeneration developed, and progressed in both male and female DMM groups, however, damage was less severe in females at the late stage of OA. Pain behavior, as measured by mechanical allodynia, was displayed for longer in male DMM mice compared to females. Incapacitance data showed that CPZ significantly reduced DMM-induced pain in male mice but not in female mice. Immunofluorescence microscopy analysis demonstrated that DMM surgery increased the expression of TRPV1 in both female and male dorsal root ganglion (DRG). Injection of CPZ significantly suppressed TRPV1 expression in the DRG of male mice only. Joint damage develops comparably in both female and male mice after DMM although it progresses less in females. There was a subtle sex difference in pain behaviors and analgesic efficacy of a TRPV1 antagonist, which was accompanied by a differential regulation of TPRV1.

Chronic non-discriminatory social defeat stress reduces effort-related motivated behaviors in male and female mice

Reward and motivation deficits are prominent symptoms in many mood disorders, including depression. Similar reward and effort-related choice behavioral tasks can be used to study aspects of motivation in both rodents and humans. Chronic stress can precipitate mood disorders in humans and maladaptive reward and motivation behaviors in male rodents. However, while depression is more prevalent in women, there is relatively little known about whether chronic stress elicits maladaptive behaviors in female rodents in effort-related motivated tasks and whether there are any behavioral sex differences. Chronic nondiscriminatory social defeat stress (CNSDS) is a variation of chronic social defeat stress that is effective in both male and female mice. We hypothesized that CNSDS would reduce effort-related motivated and reward behaviors, including reducing sensitivity to a devalued outcome, reducing breakpoint in progressive ratio, and shifting effort-related choice behavior. Separate cohorts of adult male and female C57BL/6 J mice were divided into Control or CNSDS groups, exposed to the 10-day CNSDS paradigm, and then trained and tested in instrumental reward or effort-related behaviors. CNSDS reduced motivation to lever press in progressive ratio and shifted effort-related choice behavior from a high reward to a more easily attainable low reward in both sexes. CNSDS caused more nuanced impairments in outcome devaluation. Taken together, CNSDS induces maladaptive shifts in effort-related choice and reduces motivated lever pressing in both sexes.

A sex-specific switch between visual and olfactory inputs underlies adaptive sex differences in behavior

SummaryAlthough males and females largely share the same genome and nervous system, they differ profoundly in reproductive investments and require distinct behavioral, morphological, and physiological adaptations. How can the nervous system, while bound by both developmental and biophysical constraints, produce these sex differences in behavior? Here, we uncover a novel dimorphism in Drosophila melanogaster that allows deployment of completely different behavioral repertoires in males and females with minimum changes to circuit architecture. Sexual differentiation of only a small number of higher order neurons in the brain leads to a change in connectivity related to the primary reproductive needs of both sexes—courtship pursuit in males and communal oviposition in females. This study explains how an apparently similar brain generates distinct behavioral repertoires in the two sexes and presents a fundamental principle of neural circuit organization that may be extended to other species.

Gendered movement ecology and landscape use in Hadza hunter-gatherers

Understanding how gendered economic roles structure space use is critical to evolutionary models of foraging behaviour, social organization and cognition. Here, we examine hunter-gatherer spatial behaviour on a very large scale, using GPS devices worn by Hadza foragers to record 2,078 person-days of movement. Theory in movement ecology suggests that the density and mobility of targeted foods should predict spatial behaviour and that strong gender differences should arise in a hunter-gatherer context. As predicted, we find that men walked further per day, explored more land, followed more sinuous paths and were more likely to be alone. These data are consistent with the ecology of male- and female-targeted foods and suggest that male landscape use is more navigationally challenging in this hunter-gatherer context. Comparisons of Hadza space use with space use data available for non-human primates suggest that the sexual division of labour likely co-evolved with increased sex differences in spatial behaviour and landscape use.

Behavioral Differences between Male and Hermaphrodite C. elegans.

C. elegans are microscopic nematodes used extensively as a model organism due to their simplicity, allowing researchers to study basic molecular processes in biology. Most C. elegans are hermaphrodites, possessing two X chromosomes and the ability to reproduce asexually, but approximately 0.1% are males, arising due to a spontaneous loss of an X chromosome. In order to evaluate the behavioral sex differences in C. elegans, we expanded upon existing literature and compared spontaneous movement, sensitivity to mechanosensation, and sensitivity to chemosensation between males and hermaphrodites. In our paradigms, we found that males and hermaphrodites exhibit similar spontaneous movement as well as similar slow and sustained behaviors such as chemotaxis, but differ in quick-response to mechanical and chemosensory stimuli.

National Variations in CAG Repeats of Men’s Androgen Receptor Gene: A Tabulated Review

As the mediator of androgen actions, the androgen receptor (AR) plays a central role in establishing both physical and behavioral sex differences. The AR gene contains a CAG repeat polymorphism that is related to the strength of androgen actions on target tissues and that is correlated with various health-related conditions, especially prostate cancer and infertility. Some studies have also linked the number of AR CAG repeats with behavioral and mental health factors. The present study provides a tabulated summary of the average number of AR CAG repeats for males according to the countries in which each study was conducted, thereby allowing future research to correlate national average AR CAG repeats with national variations in physical, medical and behavioral traits. Findings are summarized in two tables. The first table lists results from each of 187 studies of a total of 57,826 research participants according to the country in which each study was conducted. In the second table, the results from the first table are condensed down to the average number of AR CAG repeats for each of the 78 countries from which samples were drawn.

Sex-specific associations between subcortical morphometry in childhood and adult alcohol consumption: A 17-year follow-up study

Men and women tend to differ in the age of first alcohol consumption, transition into disordered drinking, and the prevalence of alcohol use disorder. Here, we use a unique longitudinal dataset to test for potentially predispositonal sex-biases in brain organization prior to initial alcohol exposure. Our study combines measures of subcortical morphometry gathered in alcohol naive individuals during childhood (mean age: 9.43 years, SD = 2.06) with self-report measures of alcohol use in the same individuals an average of 17 years later (N = 81, 46 males, 35 females). We observe that pediatric amygdala and hippocampus volume both show sex-biased relationships with adult drinking. Specifically, females show a stronger association between subcortical volumetric reductions in childhood and peak drinking in adulthood as compared to males. Detailed analysis of subcortical shape localizes these effects to the rostro-medial hippocampus and basolateral amygdala subnuclei. In contrast, we did not observe sex-specific associations between striatal anatomy and peak alcohol consumption. These results are consistent with a model in which organization of the amygdala and hippocampus in childhood is more relevant for subsequent patterns of peak alcohol use in females as compared to males. Differential neuroanatomical precursors of alcohol use in males and females could provide a potential developmental basis for well recognized sex-differences in alcohol use behaviors.. Thus, our findings not only indicate that brain correlates of human alcohol consumption are manifest long before alcohol initiation, but that some of these correlates are not equivalent between males and females.

Effect of Tank Size on Zebrafish Behavior and Physiology.

Simple SummaryLiving space is an important aspect of animal welfare. Understanding the effects of welfare on experimental animals would help in drawing a precise conclusion. In this work, zebrafish in different tank sizes were studied through behavioral and physiology tests. Results showed that changes in the tank size affected zebrafish behavior; those that lived in small tanks behaved less boldly, had poor stamina, and spent much time on movement. Therefore, researchers should focus on zebrafish’s living space to generate valid data from laboratory studies.Environmental conditions strongly affect experimental animals. As a model organism, zebrafish has become important in life science studies. However, the potential effect of living environment on their behavior and physiology is often overlooked. This work aimed to determine whether tank size affects zebrafish behavior and physiology. Tests on shelter leaving, shelter seeking, shoaling, stamina, and pepsin and cortisol levels were conducted. Results showed that zebrafish behavior is easily affected by changes on the tank size. Fish that lived in small tanks behaved less boldly, had poor stamina, and spent much time on movement. Sex differences in behavior were only evident in the shelter seeking tests. Tank size had no effect on pepsin and cortisol, but cortisol concentrations in males were lower than those in females. This study suggests that zebrafish behavior is easily influenced by their living environment, and future related studies should consider their living space.

Sex differences in pregabalin-seeking like behavior in a conditioned place preference paradigm

Substance abuse is a chronic, relapsing disorder characterized by compulsive drug use regardless of negative consequences. Incremental increases in pregabalin abuse have been observed in Saudi Arabia and throughout the world. In previous studies, the potential for pregabalin abuse with escalating doses of the drug (30, 60, 90, and 120 mg/kg) were investigated in male mice. Notably, researchers have argued that women may exhibit a greater tendency to consume drugs without a prescription to alleviate stress and depression. Moreover, female subjects are more prone to impulsivity in drug intake or abuse than their male counterparts. Therefore, in the present study, we compared the potential for pregabalin abuse between male and female mice using a conditioned place preference paradigm. Male and female BALB/c mice were divided into four groups based on the pregabalin dose administered (30, 60, 90, or 120 mg/kg, intraperitoneal). Preference scores were then calculated and compared between male and female mice in each dosage group. Interestingly, preference scores were significantly higher in female mice than in male mice at dosages of 30 and 120 mg/kg. These findings indicate that female mice may be more prone to pregabalin abuse and tolerance than male mice. These results might be helpful to the healthcare providers and policymakers to consider these sex differences in choosing therapeutic plans and consider alternatives to the misused prescription medications.

Sex differences in behavioral and brain responses to incongruity in emotional speech controlling for autistic traits

Accurate interpretation of speech requires the integration of verbal and nonverbal signals. This study investigated sex differences in behavior and neural activities associated with the integration of semantic content and emotional speech prosody, while the level of autistic traits was controlled for. Adults listened to Cantonese words spoken with happy and sad prosody, and made judgments on semantic valence while event-related potentials (ERP) were recorded. Behaviorally, men were slower than women in making semantic valence judgments. At the neural level, men had a greater congruity effect in the N400 component, whereas women had a greater congruity effect in the 1150–1300 ms time window for happy prosodies. There was no effect of sex in case of sad prosodies. Our study reveals novel findings on sex differences in the timing of the integration between verbal and non-verbal signals that cannot be explained by differences in autistic traits.

Vulnerability of northern gannets to offshore wind farms; seasonal and sex-specific collision risk and demographic consequences

There is a pressing need to quantify the risks of renewable energy developments such as offshore wind farms for protected populations. However, assessments are often based on incomplete data, or fail to consider variation in risk between sexes and at different times of year. We tracked northern gannets foraging from the world's largest colony (Bass Rock, Scotland) across five consecutive breeding seasons. We examine how seasonal and sex differences in behaviour affect the collision risk from planned and operational wind farms within their foraging range and assess the likely consequences for long-term population viability. Both sexes made shorter trips during chick-rearing than prior to chick-hatching, spent a greater proportion of time within wind farm sites and had an eight times greater potential collision risk during chick-rearing. Females made longer trips than males at both these times of year, flew higher and spent more time within wind farm sites, leading to three times greater collision risk for females. After accounting for the potential additional mortality from collisions, and assuming that the death of a parent also led to the loss of its offspring, the breeding population was projected to increase by 3.57% (95% CI: 2.16–5.15%) per year, compared with 6.56% (95% CI: 4.59–8.73%) in the absence of turbines, suggesting a negligible effect on population viability. However, additional mortality could result in greater immigration from neighbouring colonies, potentially affecting their viability and highlighting a need for research within a metapopulation framework to assess the impacts of offshore wind developments on vulnerable species across multiple connected sites.

Habitat and sex effects on behaviour in fawn-footed mosaic-tailed rats (Melomys cervinipes)

Habitat complexity reflects resource availability and predation pressure – both factors that influence behaviour. We investigated whether exploratory behaviour and activity varied in fawn-footed mosaic-tailed rats (Melomys cervinipes) from two habitats that were categorised differently based on vegetation. We conducted vegetation surveys to determine structural complexity and vegetation cover, confirming that an abandoned hoop-pine (Araucaria cunninghami) plantation forest was structurally less complex, with lower vegetation cover than a variable secondary rainforest. We then tested mosaic-tailed rats from both sites in four behavioural tests designed to assess exploratory and activity behaviours (open field, novel object, light-dark box, acoustic startle), predicting that rats from the less structurally complex habitat would be less exploratory, and show lower activity. Our results provide some evidence for a context-specific trade-off between exploratory behaviour and predation risk in rats from the abandoned hoop pine plantation, as rats were less active, and showed a freezing strategy in the light-dark box. We also found context-specific sex differences in behaviour in response to a novel object and sound. Our results suggest that small-scale variation in habitat structure and complexity, as well as sex differences, is associated with variation in behaviour, most likely through effects on resource availability and/or predation risk.

Worry About the Future Health Issues of Smoking and Intention to Screen for Lung Cancer With Low-Dose Computed Tomography.

Early diagnosis of lung cancer is key to improving the long-term prognosis for many individuals. Still, utilization rates of lung cancer screening (LCS) remain low. To investigate the association between worry about future health issues of smoking and intention to undergo recommended LCS with low-dose computed tomography (LDCT) within the next 3 months. A cross-sectional online survey was conducted using the Qualtrics Panel to recruit adult smokers between ages 54 and 75 years, with no history of lung cancer, and at least 30-pack-year smoking history (n = 152). The survey gathered demographic, socioeconomic, and psychographic information, including intention to screen for lung cancer with LDCT and worry about the future health issues of smoking. Data were analyzed using multivariable logistic regression. Approximately 43.0% were White, 21.7% were Black, and 60.0% were female. Most (86.0%) reported intentions to undergo recommended LCS with LDCT in the next 3 months. More than one-third (32.0%) reported moderately/very worried about the future health issues of smoking. Smokers who were moderately/very worried had 20% (P = .022) higher odds of reporting an intention to undergo LCS with LDCT than those who were not at all or a little worried. Most eligible adults reported intentions to undergo LCS with LDCT. Our study also highlights sex, racial, and socioeconomic differences in LCS behavior. The study findings provide an opportunity for healthcare providers to have in-depth discussions about the benefits of LCS with those who express worry about future health issues of smoking.

The sequel to COVID-19: the antithesis to life

The sequel to COVID-19: the antithesis to life

A non-invasive method for sexing first and second instar larvae of termites using external morphology

Division of labor is fundamental to the ecological success of social insects. In termites, both sexes engage in social tasks, and the sexual division of labor is common in many taxa. Each caste consisting of both sexes is supplied from the population of newly hatched larvae. To understand their social system, it is necessary to investigate the influence of larval sex composition on their developmental fate. However, no method currently exists for sexing young larvae non-invasively, which is essential for experimental manipulation of the sex composition in a society. Here, we report on sex-specific characteristics of the first and second instar larvae of the subterranean termite Reticulitermes speratus. Male larvae possess bristles near the center of the posterior margin of the eighth abdominal sternite that are absent in females. The bristles are detectable under a stereomicroscope without damaging the young instar larvae. The validity of morphological sexing was confirmed by a known sex-specific genetic marker. The sex-specific bristles were also useful to identify the sex of first and second instar larvae of the damp-wood termite Zootermopsis nevadensis, suggesting that morphological sexing is possible for a wide range of termite species. The morphological sexing presented here has broad applicability in studies addressing sex differences in development, caste differentiation, and behavior. These approaches will contribute to understanding why both sexes co-exist in a termite society and allocate tasks, and which tasks are completely compensable by the other sex, thereby deepening our understanding of social systems where both sexes engage in tasks.

A systematic review and meta-analysis of behavioural sex differences in executive control.

Literature investigating whether an individuals' sex affects their executive control abilities and performance on cognitive tasks in a normative population has been contradictory and inconclusive. Using meta-analytic procedures (abiding by PRISMA guidelines), this study attempts to identify the magnitude of behavioural sex differences in three prominent executive control domains of cognitive set-shifting, performance monitoring, and response inhibition. PubMed, Web of Science, and Scopus were systematically searched. Across 46 included studies, a total of 1988 females and 1884 males were included in the analysis. Overall, males and females did not differ on performance in any of the three domains of performance monitoring, response inhibition, or cognitive set-shifting. Task-specific sex differences were observed in the domains of performance monitoring, in the CANTAB Spatial Working Memory task-males scored statistically higher than females (Hedges' g=-0.60), and response inhibition, in the Delay Discounting task-females scored statistically higher than males (Hedges' g=0.64). While the meta-analysis did not detect overall behavioural sex differences in executive control, significant heterogeneity and task-specific sex differences were found. To further understand sex differences within these specific tasks and domains, future research must better control for age and sex hormone levels.