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Social disequilibrium, or disrupted social homeostasis, underlies many behavioral disorders, including problematic drug use. One way to study the relationship between drug use and social homeostasis is to determine whether single doses of psychoactive drugs relieve some of the discomfort of social isolation and promote social connection. In this narrative review, we discuss challenges and opportunities in studying the relationship between psychoactive drugs and social homeostasis. Using the examples of opioids and amphetamines, we discuss the evidence that drugs alleviate dysphoria related to lack of social connection or produce prosocial effects that improve connection. With regard to opioid drugs, we report that mu opioid agonists and kappa opioid antagonists reduce distress from social isolation, and mu opioid agonists enhance social reward. Amphetamine-like stimulant drugs, including MDMA, do not seem to act by reducing the distress of social isolation, but they have notable prosocial effects that increase both motivation for social contact and the pleasure derived from interacting socially. Many questions remain in understanding interactions between drugs and social equilibrium, including whether these effects contribute to problematic drug use. We identify gaps in knowledge, including the effects of drug withdrawal or dependence on social function or the responses of individuals with psychiatric symptomatology. Understanding these actions on social processes will help to develop novel pharmacological treatments for clinical problems related to social disequilibrium., (Copyright © 2024 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.)

Summary. The current biopsychosocial paradigm in medicine and medical psychology ensures the development of the theory and methodology of medical psychodiagnostics as a comprehensive study of psychological and psychosocial factors underlying mental adaptation. The diagnostic of prenosological and initial manifestations of borderline spectrum disorders designated as adjustment disorders in ICD-10 (F43.2), requires the criteria qualification of real or potential stressogenic social functioning conditions, thus, an arsenal of adequate methods of clinical and medical-psychosocial psychodiagnostics is required. The questionnaire «Social Frustration Level» represents one of such methods. The study of social frustration phenomenon as a predictor of emotional tension and stress resistance allows to characterize personality traits in relation to environmental influence and assess the specificity and pathogenic significance of socially frustrating factors. The article substantiates theoretical and methodological foundations of the questionnaire, its attributive characteristics — the phenomena of external and internal social frustration identified in medical psychodiagnostics for the first time. Socio-diagnostic criteria are illustrated by examples of the practical use in medical psychodiagnostics of social frustration in teachers of mass schools, the military and in patients with focal epilepsy. The specified research contingent is united by the problem of stress resistance in crisis situations (including a disease situation and the attitude to the disease). The questionnaire «Social Frustration Level» can be considered as a necessary form of psychosocial diagnostics of stress genesis, a source of information in screening psychoprophylactic studies, as well as in the forming of indications for psycho- and sociotherapy.

Abstract Density-dependent change in aggressive behavior contributes to the population regulation of many small rodents, but the underlying neurological mechanisms have not been examined in field conditions. We hypothesized that crowding stress and aggression-associated oxytocin (OT) and arginine vasopressin (AVP) in specific regions of the brain may be closely related to aggressive behaviors and population changes of small rodents. We analyzed the association of OT and AVP expression, aggressive behavior, and population density of Brandt’s voles in 24 large semi-natural enclosures (0.48 ha each) in Inner Mongolia grassland. We tested the effects of population density on the OT/AVP system and aggressive behavior by experimentally manipulating populations of Brandt’s voles in the grassland enclosures. High density was positively and significantly associated with more aggressive behavior, and increased expression of mRNA and protein of AVP and its receptor, but decreased expression of mRNA and protein of OT and its receptor in specific brain regions of the voles. Our study suggests that changes in OT/AVP expression are likely a result of the increased psychosocial stress that these voles experience during overcrowding, and thus the OT/AVP system can be used as indicators of density-dependent stressors in Brandt’s voles.

Chronic social stress has been epidemiologically linked to increased risk for cardiovascular disease, yet the underlying pathophysiological mechanisms are still largely elusive. Mitochondrial (dys)function represents a potential intersection point between social stress exposure and (mal)adaptive cardiac responses. In this study, we used a rodent model of social stress to study the extent to which alterations in the cellular mechanical properties of the heart were associated with changes in indexes of mitochondrial function. Male adult rats were exposed to repeated episodes of social defeat stress or left undisturbed (controls). ECG signals were recorded during and after social defeat stress. Twenty-four hours after the last social defeat, cardiomyocytes were isolated for analyses of mechanical properties and intracellular Ca2+ dynamics, mitochondrial respiration, and ATP content. Results indicated that social defeat stress induced potent cardiac sympathetic activation that lasted well beyond stress exposure. Moreover, cardiomyocytes of stressed rats showed poor contractile performance (e.g., slower contraction and relaxation rates) and intracellular Ca2+ derangement (e.g., slower Ca2+ clearing), which were associated with indexes of reduced reserve respiratory capacity and decreased ATP production. In conclusion, this study suggests that repeated social stress provokes impaired cardiomyocyte contractile performance and signs of altered mitochondrial bioenergetics in the rat heart. Future studies are needed to clarify the causal link between cardiac and mitochondrial functional remodeling under conditions of chronic social stress.

Social behaviors have become more relevant to our understanding of the human nervous system because relationships with our peers may require and modulate adult neurogenesis. Here, we review the pieces of evidence we have to date for the divergence of social behaviors in mice by modulation of adult neurogenesis or if social behaviors and the social environment can drive a change in neurogenic processes. Social recognition and memory are deeply affected by antimitotic drugs and irradiation, while NSC transgenic mice may run with lower levels of social discrimination. Interestingly, social living conditions can create a big impact on neurogenesis. Social isolation and social defeat reduce the number of new neurons, while social dominance and enrichment of the social environment increase their number. These new “social neurons” trigger functional modifications with amazing transgenerational effects. All of these suggest that we are facing two bidirectional intertwined variables, and the great challenge now is to understand the cellular and genetic mechanisms that allow this relationship to be used therapeutically.

A disorder known as mental illness alters a personal's emotions, thoughts, or behaviour. Any of these elements alone or in combination may cause it. If stress cannot be managed, people of all ages, races, religions, sexes, and nationalities can develop mental illnesses. The development of mental diseases is significantly influenced by stress. Risk factors for mental illness and social stress include academic stress, socioeconomic position, and financial difficulties. All of these risk variables are challenging to pinpoint because they come from many environments. The purpose of this study is to identify the key aspects that students experience that contribute to mental illness and social stress, as well as to rank those factors by using Fuzzy Technique for Order Preference by Similarity to Ideal Solution (TOPSIS). This study ranks social life, academic life, and financial status as the three factors that have the greatest influence on mental illness and social stress among college students. The following evaluation criteria are used to grade the components: family background, educational attainment, physical health, and mode of study. Additionally, Fuzzy TOPSIS is used to rank the variables according to correlation. The issues in this study are evaluated by three decision-makers using linguistic characteristics ranging from "very affected" to "not affected". With a proximity value of 0.469, the research demonstrates that academic life has a significant impact on students' mental health and social stress. With a closeness coefficient of 0.358, social life is the least significant factor. The results of this study may be useful to many people, including parents, counsellors, and the kids themselves. The project's scope could be expanded in the future by adding a range of criteria and options.

Age is a major risk factor for chronic infections, including tuberculosis (TB). Elderly TB patients also suffer from elevated levels of psychological stress. It is not clear how psychological stress impacts immune response to Mycobacterium tuberculosis (M.tb). In this study, we used social disruption stress (SDR) to investigate effects of psychological stress in young and old mice. Unexpectedly, we found that SDR suppresses lung inflammation in old mice as evidenced by lower pro-inflammatory cytokine levels in bronchial lavage fluid and decreased cytokine mRNA expression by alveolar macrophages. To investigate effects of stress on M.tb infection, mice were subjected to SDR and then infected with M.tb. As previously reported, old mice were better at controlling infection at 30 days than young mice. This control was transient as CFUs at 60 days were higher in old control mice compared to young mice. Consistently, SDR significantly increased M.tb growth at 60 days in old mice compared to young mice. In addition, SDR in old mice resulted in accumulation of IL-10 mRNA and decreased IFN-γ mRNA at 60 days. Also, confocal microscopy of lung sections from old SDR mice showed increased number of CD4 T cells which express LAG3 and CD49b, markers of IL-10 secreting regulatory T cells. Further, we also demonstrated that CD4 T cells from old SDR mice express IL-10. Thus, we conclude that psychological stress in old mice prior to infection, increases differentiation of IL-10 secreting T cells, which over time results in loss of control of the infection.

This study aimed to investigate the mechanism underlying social stress (SS)-induced erectile dysfunction (ED) and evaluate the effects of a single subanesthetic dose of ketamine on SS-related ED. Male FVB mice were exposed to retired male C57BL/6 mice for 60 min daily over a 4-week period. In the third week, these FVB mice received intraperitoneal injections of either saline (SSS group) or ketamine (SSK group). Erectile function was assessed by measuring the intracavernosal pressure (ICP) during electrical stimulation of the major pelvic ganglia. Corpus cavernosum (CC) strips were utilized for wire myography to assess their reactivity. Both SSS and SSK mice exhibited significantly lower ICP in response to electrical stimulation than control mice. SS mice showed increased contractility of the CC induced by phenylephrine. Acetylcholine-induced relaxation was significantly reduced in SSS and SSK mice. Sodium nitroprusside-induced relaxation was higher in SSS mice compared to control and SSK mice. Nicotine-induced neurogenic and nitric oxide-dependent relaxation was significantly impaired in both SSS and SSK mice. An immunohistochemical analysis revealed co-localization of tyrosine hydroxylase and neuronal nitric oxide synthase-immunoreactive fibers in the CC. These findings highlight the complex nature of SS-related ED and suggest the limited efficacy of ketamine as a therapeutic intervention.

Social stress is a major contributor to neuropsychiatric issues such as depression, substance abuse and eating disorders. The ventral tegmental area (VTA) is involved in the effects of stress on cognitive and emotional processes perturbed in these disorders. However, the VTA is a cellularly heterogeneous brain area and it remains unclear which of its neuronal populations make up the social stress-sensitive ensemble. The current study characterizes the molecular, topographical and functional properties of VTA social stress-activated cells. First, we used immunohistochemical analysis of Fos protein, a marker of recent increased neuronal activity, to show that acute social stress activates a mainly neuronal ensemble in the VTA (VTASocial stress neurons). Topographical analysis showed that this ensemble, which comprises ==11% of all VTA neurons, occurs across VTA subregions. Further analysis showed that approximately half of the VTASocial stress neurons express the dopamine synthesis rate-limiting enzyme tyrosine hydroxylase (TH). In a minority of cases this occurred with coexpression of vesicular glutamate transporter 2 (Vglut2). Also part of the ensemble were VTA cells expressing just Vglut2 without TH, and cells expressing the vesicular GABA transporter (VGAT) without TH. Next, using targeted recombination in active populations (TRAP2), we showed that VTASocial stress neurons can be permanently tagged and made tractable for future functional investigations. Using a combination of TRAP2 and patch-clamp electrophysiology we demonstrate that VTASocial stress neurons exhibit higher excitability than their non-TRAPed neighbor cells. Overall, this study shows that acute social stress activates an ensemble of neurons throughout the VTA, comprising distinct molecular identities, and with specific electrophysiological features. It also identifies TRAP2 as a tool to make this ensemble tractable for future functional studies. [ABSTRACT FROM AUTHOR]

A hitherto unidentified underlying basis of the globally ubiquitous demographic transition is suspected from causality-testing economic models, problems with anthropological hypotheses, and the longstanding opacity of aetiology unrelieved by integrating theory from different fields. Given a newly found main factor of population density, there is an apparent biological basis that rather than out-breeding depression is likely the now-replicated finding of chronic crowding stress of male mammals epigenetically transmitted to female offspring only, triggering multi-generational fertility decline and aberrant reproduction-related behaviours. The mechanistic core is found in humans. It's adaptive in aiding natal-group survival of neighbouring-group hostility, through exogamous natal-group females severely compromising out-group male reproduction, without impeding that of natal-group males; this complementing apparent female clique-based facultative co-operative breeding. [ABSTRACT FROM AUTHOR]

Two highly overriding problems that the society is facing today are stress and obesity. This narrative review article explains the vicious cycle of how stress leads to obesity and vice versa. Stress and obesity are interconnected to each other through different lines of cognition, behavior, and physiology. Stress can interfere with cognitive processes like self-regulation. Stress can also influence behavior by indulging in overeating of foods that are high in calories, fat, and sugar. Stress also invigorates the generation of biochemical hormones and peptides, for example, leptin, ghrelin, and neuropeptide Y. This article also extracts the contribution of weight stigma and social stress in producing obesity in an obesogenic process. Recent Studies describe that psychological distress and elevated cortisol secretion promote abdominal fat, a feature of the metabolic syndrome, improvements in mindfulness, chronic stress, and cortisol awakening response (CAR) were associated with reductions in abdominal fat. Mindfulness intervention for stress suggests that mindfulness training improves eating patterns and the CAR, which may reduce abdominal fat over time. Obesity has a multifaceted etiology. In this review, several factors of stress are identified that affect the development of obesity. This review also provides valuable insight into the relationship between obesity and stress. [ABSTRACT FROM AUTHOR]

Social stress is a widely experienced problem in the contemporary world; it is diverse and is determined by specific living conditions in both humans and animals. Isolation stress and crowding stress are chronic states which are actively and effectively modeled in rodents. The aim of the present work was to study the influences of these types of social stress in rats on the rate of learning to complete an operant food-procuring behavior alone and in cooperation with a conspecific. Blood corticosterone and ACTH levels were measured to assess the state of the stress-mediating hypothalamo-hypophyseal-adrenocortical system (HHACS); neurotrophins and proinflammatory cytokines were also estimated. Isolation stress, in contrast to crowding, decreased learning effectiveness – formation of a new skill – in both individual and cooperative behavior. No increases in HHACS functioning were seen in stressed animals of either group. Furthermore, animals in crowded conditions showed significant reductions in corticosterone and increases in the proinflammatory cytokine IL-1β. These results suggest that the mechanisms of action of chronic isolation and crowding stress are different both at the level of the stress-mediating system of the body and at the level of their influences on integrative brain activity. [ABSTRACT FROM AUTHOR]

Sleep problems have become a public health epidemic with recent data suggesting that over 69% of US adults get less sleep than they need. Despite the important role that sleep plays in our lives, sleep as a variable of interest in interpersonal processes has been historically absent from the psychological literature. Recently, however, researchers have shed some light on the link between sleep and a wide array of social processes. This work illuminates the important role that sleep plays in our social experiences, from basic social perception to complex social interactions. We outline a working model for the bidirectional link between sleep and social processes, including underlying mechanisms, review the recent research that informs this model, and use it to elucidate important next steps to bring together sleep and social psychological research. We also address the pragmatics of measuring sleep for non-sleep researchers.

ObjectiveUnderstanding individual differences in the psychobiology of the stress response is critical to grasping how psychosocial factors contribute to racial and ethnic health disparities. However, the ways in which environmentally sensitive biological systems coordinate in response to acute stress is not well understood. We used a social-evaluative stress task to investigate coordination among the autonomic nervous system, hypothalamic-pituitary-adrenal axis, and immune/inflammatory system in a community sample of 85 healthy African American men and women.MethodsSix saliva samples, 2 at each of baseline, event, and recovery phases of the stressor task, were assayed for cortisol, dehydroepiandrosterone-sulfate, salivary alpha-amylase, and salivary C-reactive protein. Individual differences in perceived discrimination and racial identity were also measured.ResultsFactor analysis demonstrated that stress systems were largely dissociated before stressor exposure but became aligned during event and recovery phases into functional biological stress responses (factor loadings ≥ .58). Coordinated responses were related to interactions of perceived discrimination and racial identity: when racial identity was strong, highly perceived discrimination was associated with low hypothalamic-pituitary-adrenal axis activity at baseline (B's = .68-.72, p < .001), low stress mobilization during the task (B's = .46-.62, p < .049), and a robust inflammatory response (salivary C-reactive protein) during recovery (B's = .72-.94, p < .002).ConclusionCulturally relevant social perceptions may be linked to a specific pattern of changing alignment in biological components of the stress response. Better understanding these links may significantly advance understanding of stress-related illnesses and disparities.

Previous research has shown that adverse social conditions may promote a conserved transcriptional response to adversity (CTRA) involving up-regulation of proinflammatory gene expression and down-regulation of Type I interferon anti-viral genes in circulating blood cells. However, the impact of social conditions on lymphoid tissue gene regulation remains largely unexplored. This project assessed how social instability in adult male rhesus macaques (N=10, 5 in unstable, and 5 in stable social conditions) might regulate gene expression within secondary lymphoid tissue (lymph nodes; LN). Unstable social conditions down-regulated axillary LN expression of genes involved in Type I interferon anti-viral responses. Transcript origin analyses implicated monocytes and B cells as cellular mediators of these effects, and promoter-based bioinformatics analyses indicated reduced activity of AP-1, NF-κB, IRF, and CREB transcription factors within the axillary LN microenvironment. Although the current study is limited in sample size, these results suggest that social influences on immune cell gene regulation extend beyond the circulating leukocyte pool to alter generalized transcriptome profiles in secondary lymphoid tissue, and they do so in a regulatory program that resembles the pattern of antiviral inhibition previously observed in circulating leukocytes.

Psychosocial stressors appear to promote the onset of depressive illness through activation and sensitization of inflammatory mechanisms. Here, adult male rhesus monkeys brought from large outdoor social groups to indoor housing for 8 days reliably exhibited a hunched, depressive-like posture. When rehoused indoors a second 8 days about 2 weeks later, monkeys housed alone, but not those with an affiliative partner, showed sensitization of the depressive-like hunched posture. Housing indoors also affected circulating pro-inflammatory cytokines: IL-1β showed increased responsiveness to immune challenge, and IL-1β and TNF-α showed reduced suppression by dexamethasone. Sensitivity of the anti-inflammatory cytokine IL-10 to immune challenge exhibited a relative increase from the first to the second round of indoor housing in animals housed in pairs, and a relative decrease in animals housed alone. Cytokine levels during indoor housing were positively correlated with duration of depressive-like behavior. Plasma cortisol levels increased but did not differentiate housing conditions or rounds. Results demonstrate a rapid induction and sensitization of depressive-like behavior to indoor individual housing, social buffering of sensitization, and associated inflammatory responses. This paradigm may provide a practical nonhuman primate model for examining inflammatory-mediated consequences of psychosocial stressors on depression and possible social buffering of these effects.

Background: While witnessing the suffering of other people results in personal distress, it is not clear whether regulating others’ emotions in such situations also comes at an emotional cost for the observer. Methods: This study included 62 subjects and used a newly developed functional Magnetic Resonance Imaging (fMRI) paradigm to investigate mechanisms of self and other emotion regulation via reappraisal while the subject and an interaction partner outside the scanner were facing the same distressing situation simultaneously. The relationship between distress levels and individual differences in emotional and cognitive empathy were also assessed. Results: We found that individuals exhibited especially high levels of personal distress when relating with a partner while both being exposed to aversive photographs and that especially highly empathetic individuals were prone to such personal distress. Moreover, when engaging in social emotion regulation, personal distress was reduced in the observer at a similar rate as in self emotion regulation. FMRI analyses revealed increased activation for other vs. self emotion regulation in the precuneus and the left temporo-parietal junction, which are commonly engaged in social cognition. Furthermore, this activation was associated with lower self-reported stress and decreased sympathetic autonomic activity. While regulating others, precuneus activation exhibited a distinctive functional connectivity profile with parietal emotion regulation regions. Conclusions: This study demonstrates benefits of actively regulating another person's emotions for reducing one's own distress and identifies the precuneus as an important node for social emotion regulation. Given the novelty of the study design, the results are of exploratory and preliminary nature.

Social stress is a major contributor to neuropsychiatric issues such as depression, substance abuse and eating disorders. The ventral tegmental area (VTA) is involved in the effects of stress on cognitive and emotional processes perturbed in these disorders. However, the VTA is a cellularly heterogeneous brain area and it remains unclear which of its neuronal populations make up the social stress-sensitive ensemble. The current study characterizes the molecular, topographical and functional properties of VTA social stress-activated cells. First, we used immunohistochemical analysis of Fos protein, a marker of recent increased neuronal activity, to show that acute social stress activates a mainly neuronal ensemble in the VTA (VTASocial stress neurons). Topographical analysis showed that this ensemble, which comprises ∼11% of all VTA neurons, occurs across VTA subregions. Further analysis showed that approximately half of the VTASocial stress neurons express the dopamine synthesis rate-limiting enzyme tyrosine hydroxylase (TH). In a minority of cases this occurred with coexpression of vesicular glutamate transporter 2 (Vglut2). Also part of the ensemble were VTA cells expressing just Vglut2 without TH, and cells expressing the vesicular GABA transporter (VGAT) without TH. Next, using targeted recombination in active populations (TRAP2), we showed that VTASocial stress neurons can be permanently tagged and made tractable for future functional investigations. Using a combination of TRAP2 and patch-clamp electrophysiology we demonstrate that VTASocial stress neurons exhibit higher excitability than their non-TRAPed neighbor cells. Overall, this study shows that acute social stress activates an ensemble of neurons throughout the VTA, comprising distinct molecular identities, and with specific electrophysiological features. It also identifies TRAP2 as a tool to make this ensemble tractable for future functional studies.

Stress produces differential behavioral responses through select molecular modifications to specific neurocircuitry elements. The orexin (Orx) system targets key components of this neurocircuitry in the basolateral amygdala (BLA). We assessed the contribution of intra-BLA Orx 1 receptors (Orx 1 Rs) in the expression of stress-induced phenotypes of mice. Using the Stress Alternatives Model, a social stress paradigm that produces two behavioral phenotypes, we characterized the role of intra-BLA Orx 1 R using acute pharmacological inhibition (SB-674042) and genetic knockdown (AAV-U6-Orx 1 R-shRNA) strategies. In the BLA, we observed that Orx 1 R (H crtr 1) messenger RNA is predominantly expressed in CamKIIα+ glutamatergic neurons and rarely in GABAergic (gamma-aminobutyric acidergic) cells. While there is a slight overlap in H crtr 1 and Orx 2 receptor (H crtr 2) messenger RNA expression in the BLA, we find that these receptors are most often expressed in separate cells. Antagonism of intra-BLA Orx 1 R after phenotype formation shifted behavioral expression from stress-sensitive (Stay) to stress-resilient (Escape) responses, an effect that was mimicked by genetic knockdown. Acute inhibition of Orx 1 R in the BLA also reduced contextual and cued fear freezing responses in Stay animals. This phenotype-specific behavioral change was accompanied by biased molecular transcription favoring H crtr 2 over H crtr 1 and M apk 3 over P lcb 1 cell signaling cascades and enhanced B dnf messenger RNA. Functional reorganization of intra-BLA gene expression is produced by antagonism of Orx 1 R, which promotes elevated H crtr 2 , greater M apk 3 , and increased B dnf expression. Together, these results provide evidence for a receptor-driven mechanism that balances pro- and antistress responses within the BLA. [ABSTRACT FROM AUTHOR]

Pathogen virulence is highly variable within populations, and although many factors contributing to virulence differences are known, there is still much variation left unexplained. Identifying and characterizing environmental conditions associated with different virulence levels is therefore an important undertaking in infectious disease research. One factor considered to be a major determinant of overall health and susceptibility to disease in social animals is social status. Health differences associated with social status are thought to be caused by different levels of chronic stress in higher- versus lower-status individuals. There is considerable evidence that these effects extend to the standing immune profile and that social status directly influences susceptibility to pathogens. Here we examined the association between dominance status in male wild-derived house mice, Mus musculus , and susceptibility to Friend virus complex in the context of seminatural populations with intense male–male competition and no predation. Due to an interruption in our facility's heating system, we were unexpectedly presented with the opportunity to assess how reduced ambient temperature influences the association of host social status and pathogen virulence. Environmental temperature has been implicated as a contributor to pathogen virulence, giving us a unique chance to examine its role in a previously unexamined pathogen system, while the added context of social status can expand our understanding of how the interaction of different environmental conditions affects virulence. We found that pathogen virulence and replication were lower in socially dominant hosts compared to nondominant hosts. When temperature was reduced, cool enclosure-housed dominant males were more susceptible to infection than their warm enclosure-housed counterparts. The mechanistic underpinnings that link infectious disease and social status remain difficult to disentangle from their associated factors, but this study opens the door for future experiments using a novel approach in the most well-studied mammalian model available. • Dominant male mice had lower virulence and replication of a retroviral pathogen. • This pattern was disrupted at low ambient temperature. • We present experimental methods for studying seminatural social ecology in mice. [ABSTRACT FROM AUTHOR]

In pathological or artificial conditions, memory can be formed as silenced engrams that are unavailable for retrieval by presenting conditioned stimuli but can be artificially switched into the latent state so that natural recall is allowed. However, it remains unclear whether such different states of engrams bear any physiological significance and can be switched through physiological mechanisms. Here, we show that an acute social reward experience switches the silent memory engram into the latent state. Conversely, an acute social stress causes transient forgetting via turning a latent memory engram into a silent state. Such emotion-driven bidirectional switching between latent and silent states of engrams is mediated through regulation of Rac1 activity-dependent reversible forgetting in the hippocampus, as stress-activated Rac1 suppresses retrieval, while reward recovers silenced memory under amnesia by inhibiting Rac1. Thus, data presented reveal hippocampal Rac1 activity as the basis for emotion-mediated switching between latent and silent engrams to achieve emotion-driven behavioral flexibility. [ABSTRACT FROM AUTHOR]

Background: Psychological stress is commonly found among infertile women. Untreated stress can affect negatively the success of infertility treatment. Most of the available knowledge is generated from developed countries and is largely based on women undergoing In vitro fertilization (IVF) treatment. However, very little is known on infertile women from Ethiopia including other countries in East Africa. The aim of this study was to determine the prevalence of psychological stress and possible demographic-clinical correlates in Ethiopian women suffering from infertility. Method: This cross sectional descriptive correlation study was conducted from May to August, 2021 involving 96 women undergoing a non-IVF treatment for infertility at Gandhi Memorial and Tikur Anbessa hospitals. The sampling was continuous and based on inclusion criteria that include infertility duration of a minimum one year, female sex and Ethiopian nationality. Data on Infertility related stress was collected using the Copenhagen Multi‐Centre Psychosocial Infertility-Fertility Problem Stress questionner administered by an interviewer. The socio demographic and clinical factors were collected using Amharic version of structured interviewer administered questionnaire and chart review. The analysis of relationship between infertility related stress and background variables was done with an independent sample t-test or one-way ANOVA statistics supplemented with effect size assessment. Results: The prevalence of infertility related stress was overall 92.71% (95% CI, 87–98%). The personal, marital, and social subdomain mean scores (SD) were 2.74 (.80), 1.54 (.81) and 1.90 (.80), respectively. Infertility related stress was higher for those women who were: aged above 35, living in a cohabitation marital type, has no living children, and with 4–6 years duration of infertility (all P < 0.05). Whereas, there was insufficient evidence to suggest that infertility related stress varies by education, income, knowledge of cause of infertility or history of past treatment (all P > 0.05). Conclusions: The prevalence of psychological stress among Ethiopia women having infertility was very high. The results provide preliminary evidence that infertility related stress is associated with age, marital status, motherhood status and duration of infertility. Responsible bodies need to avail psychological screening and services prioritizing women at higher risk of developing stress. [ABSTRACT FROM AUTHOR]

Social stress can affect the ability of fish to respond to various stressors, such as pathogens or environmental variations. In this paper, the effects of social stress on gilt-head bream (Sparus aurata) were investigated. To study the effects of physiological stress, we evaluated biochemical and cellular parameters, such as cortisol, glucose, lactate, osmolarity, and phagocytosis, 24 h after the establishment of social hierarchy in a group of three fish. Social hierarchy was determined and characterized by behavioral observation (aggressive acts and feeding order) of the specimens (dominant: "α"; subordinate: "β" and "γ"). After the establishment of social hierarchy, we observed that, overall, levels of plasma cortisol and other biochemical plasmatic stress markers (glucose and lactate) were higher in subordinate individuals than in dominant individuals. In addition, the modulation of phagocytic activity of the peritoneal exudate cells (PECs) demonstrated that social stress appeared to affect immune response. Finally, principal component analysis clearly separated the subordinate fish groups from the dominant groups, based on stress markers and the phagocytic activity of peritoneal exudate cells. This study contributes to current knowledge on gilt-head sea bream, helping to understand the link between social stress, behavior, and physiology of this species, relevant in the aquaculture sector, where fish are subjected to several kinds of stress. [ABSTRACT FROM AUTHOR]

The deleterious mental health effects associated with the COVID‐19 pandemic are increasingly apparent, however, questions remain about the extent to which pandemic‐related stressor exposure has contributed to increased psychological distress among an already disadvantaged group, individuals with disabilities. The first aim of the study was to examine the distribution of pandemic‐related stressors across multiple dimensions—employment, personal and family finances, personal relationships, and quality of social life—among individuals with and without disabilities. The second aim of the study was to examine the association between a composite COVID‐19 stressor score and two mental health outcomes—depressive and anxiety symptoms—among the two subsamples. The study used quota‐based online survey data (N = 2043) collected in the summer of 2020 from adults (18 and older) residing in the Intermountain West, half of whom had a self‐reported disability. Study results demonstrated that individuals with disabilities experienced pandemic‐related stressors at significantly higher rates relative to their non‐disabled counterparts. Further, pandemic stressor exposure was associated with greater negative effects on their psychological well‐being. We argue that the COVID‐19 pandemic is generating a secondary mental illness pandemic, and that individuals with disabilities are affected by it at significantly higher proportions. [ABSTRACT FROM AUTHOR]

We studied hippocampal variability in relation to the multiyear population density cycle and the action of density-dependent autoregulatory mechanisms associated with behavior. A study of field collections of the morphological material of bank voles (Clethrionomysglareolus, Rodentia) revealed annual variability in the hippocampal size against changes in the population density. The absolute and relative mass of the hippocampus was significantly higher in young autumn voles in the year of population peak against the background of a pronounced stress reaction manifested in an increased mass of the adrenal glands. This peculiarity of brain morphology persisted throughout the life cycle of animals born in the year of a population peak. Possible factors and mechanisms of hippocampal variability in connection with the dynamics of population density are discussed. [ABSTRACT FROM AUTHOR]

Summary: The present study goal was to provide further information on the association of maltreatment experiences in childhood (CM) and impaired sleep taking the hyperarousal theory of insomnia and stress reaction into account. In all, 62 participants took part in the study. CM history (Childhood Trauma Questionnaire) and subjective sleep quality (Pittsburgh Sleep Quality Index) were assessed before study commencement. In addition, participants wore an actigraph for 6–7 consecutive nights and completed a sleep log during this time. After 3–4 days, the participants took part in a laboratory stress paradigm (Maastricht Acute Stress Test) with 29 participants in the experimental and 31 in the control condition. Saliva cortisol samples were taken before and after the experiment and heart rate variability was assessed. CM was positively correlated with impaired subjectively assessed sleep in adulthood. The stress manipulation led to heightened subjective and physiological stress. Although lower cortisol changes after and lower mean heart rate values during the stress induction were found in the CM group, the differences were not statistically significant. There was no observable sleep reactivity on the stress induction. Stress and CM appear to have long‐term effects on subjective sleep. Acute social stress does not directly worsen sleep quality, neither in participants with nor without a history of CM. However, the association underlines the importance of prevention and intervention. When treating sleep impairments, potential CM experiences should be taken into account. [ABSTRACT FROM AUTHOR]

Introduction: Corticotropin-Releasing Hormone (CRH) is involved in stress and energy homeostasis. On the other hand, CRH receptors also exist within the paraventricular nucleus (PVN) and Central Amygdala (CeA) nuclei. The present study compared the effect of CRH microinjections into PVN and CeA on three consecutive hours and cumulative food intake, internal regulatory factors of food intake, such as serum leptin and ghrelin, as well as blood glucose levels in rats under different acute psychological (Social Stress [SS] and Isolation Stress [IS] group) stresses. Methods: Sixty-six male Wistar rats were randomly allocated to 11 groups: Control, Sham, CRH-PVN, CRH-CeA, SS, IS, SS-CRH-PVN, SS-CRH-CeA, IS-CRH-PVN, and IS-CRH-CeA groups. The CRH (2 µg/kg in 0.5 µL saline) was injected into PVN and CeA nuclei in rats under everyday, acute social stress and isolation stress conditions. Results: Acute isolation and social stresses did not affect cumulative food intake. Whereas isolation stress led to changes in both leptin and glucose levels, social stress reduced only glucose levels. Cumulative food intake significantly decreased under acute CRH injection into the CeA and particularly into the PVN. Blood glucose significantly reduced in all the groups receiving CRH into their CeA. Conclusion: The PVN played a more important role compared to CeA on food intake. These nuclei probably employ different mechanisms for their effects on food intake. Besides, it seems that exogenously CRH injection into the PVN probably had a more anorectic effect than naturally activated CRH by stresses. Acute isolation stress had a greater impact than social stress on leptin level and cumulative food intake. Thus, elevated food intake related to leptin compared to ghrelin and glucose levels in the CRH-PVN group under acute social stress.

Objective. Systematization of the main factors of psychological and psychiatric risk during the COVID-19 pandemic, identified in foreign studies. Background. The need to clarify ideas about the determination of psychological and psychiatric problems caused by the socially stressful impact of the COVID-19 pandemic is dictated primarily by the demands of practice. The relevance of actions in this direction is determined by the continuing instability of the epidemiological and socio-economic situation, the need for prompt and wide coverage of those in need with programs of psychological and psychiatric care, the fragmentation and inconsistency of exist- ing information about the impact of the pandemic on the mental health of the population. Methodology. A theoretical analysis of literature sources describing foreign studies of psychologi- cal and psychiatric risk factors against the background of a pandemic was carried out; using a compara- tive analytical method, the meaning and degree of knowledge of situational and individual factors are determined. Conclusions. The general features of studies conducted by psychologists and psychiatrists from different countries against the background of the coronavirus threat were revealed (the predominance of the remote format, the reduction in the variety and volume of diagnostic tools, the use of large-scale samples). The main factors of psychological and psychiatric risk affecting the population in the context of the spread of coronavirus are divided into situational and individual. The factors of the first group are differentiated according to their degree of specificity for the COVID-19 pandemic, while in the second group, socio-demographic and medico-psychological factors are distinguished. It is shown that indi- vidual psychological characteristics that can determine the nature of a person’s response to a pandemic remain the least studied and clarification of their composition is an urgent scientific and practical task.

Over 50% of patients are resistant to current treatments for depression. With a lifetime prevalence of 20.6% among US adults, it is evident that the present understanding of major depressive disorder is limited, and current experimental methods are inadequate to decode the complex pathology of depression. This study used a novel animal model, Repeated Forced Social Defeat, to induce depressive-like symptoms in mice in order to add to the current literature on depression. The study sample comprised forty wild type male C57BL/6 inbred mice. The Tube Test was utilized to determine the established social rankings within each group of mice. This was followed by administration of the Tail Suspension Test and a second administration of the Tube Test. Repeated Forced Social Defeat was administered a week after the second round of Tube Test administration, followed by one last round of the Tail Suspension Test. Results indicate that the dominant mice did not display significantly greater immobility times than the subordinate mice in the Tail Suspension test prior to- and after administration of Repeated Forced Social Defeat. However, there was a non-significant trend towards the dominant mice displaying greater immobility times in comparison to the subordinate mice post social defeat. Evidently, while there were no significant differences, dominant mice seem to display less resilience following social defeat in comparison to subordinate mice. A possible explanation for a lack of significant differences is a small sample size and short period of administration. These findings demonstrate the potential of utilizing Repeated Forced Social Defeat as a means to induce depressive-like symptoms in mice, as well as the relevance of dominance hierarchies in predicting susceptibility to specific stressors. Further investigation of Repeated Forced Social Defeat is warranted.

This study is devoted to the experimental study of the immunocorrecting action of Semax (Met-Glu-His-Phe-Pro-Gly-Pro) and Selank (Thr-Lys-Pro-Arg-Pro-Gly-Pro) on the model of "social" stress formed as a result of sensory contact and inter-confrontation. Functional activity of the immune system of laboratory animals was assessed on the basis of standard immunopharmacological tests: delayed-type hypersensitivity reaction (DTH), direct agglutination test (DAT), latex test for studying the phagocytic activity of peripheral blood neutrophils, and evaluation of changes in the leukocyte formula. As a result of the experiment, it was found that, under the influence of "social" stress, changes in the immune response are multidirectional, which confirms the theory of "immune disbalance" under the action of stressors. As a result of studying the influence of Semax and Selank on the model of "social" stress, it was found that the drug proved to be an effective corrector, restoring the cellular and humoral immunogenesis reactions, the phagocytic activity of neutrophils, which indicates the presence of immunomodulating properties, and emphasizes the need for further studies in this scientific direction. This study expands the scientific research base in the field of immunoreaction under stress-induced conditions with the aim of further developing a pharmacological strategy for correcting the revealed disorders by means of substances of a neuropeptide structure. [ABSTRACT FROM AUTHOR]

Over 50% of patients are resistant to current treatments for depression. With a lifetime prevalence of 20.6% among US adults, it is evident that the present understanding of major depressive disorder is limited, and current experimental methods are inadequate to decode the complex pathology of depression. This study used a novel animal model, Repeated Forced Social Defeat, to induce depressive-like symptoms in mice in order to add to the current literature on depression. The study sample comprised forty wild type male C57BL/6 inbred mice. The Tube Test was utilized to determine the established social rankings within each group of mice. This was followed by administration of the Tail Suspension Test and a second administration of the Tube Test. Repeated Forced Social Defeat was administered a week after the second round of Tube Test administration, followed by one last round of the Tail Suspension Test. Results indicate that the dominant mice did not display significantly greater immobility times than the subordinate mice in the Tail Suspension test prior to- and after administration of Repeated Forced Social Defeat. However, there was a non-significant trend towards the dominant mice displaying greater immobility times in comparison to the subordinate mice post social defeat. Evidently, while there were no significant differences, dominant mice seem to display less resilience following social defeat in comparison to subordinate mice. A possible explanation for a lack of significant differences is a small sample size and short period of administration. These findings demonstrate the potential of utilizing Repeated Forced Social Defeat as a means to induce depressive-like symptoms in mice, as well as the relevance of dominance hierarchies in predicting susceptibility to specific stressors. Further investigation of Repeated Forced Social Defeat is warranted. [ABSTRACT FROM AUTHOR]

Stress is one of the main risk factors that can induce humans to develop disorders such as depression, anxiety, or drug use. One of the main sources of stress is social interaction, which can lead to situations like bullying at school or work. In this article we will review the close relationship between exposure to stressful situations and increased cocaine or alcohol use. We will also present the main results obtained with animal models, which have allowed researchers to study the brain mechanisms involved in the impact of stress on drug use. To conclude, we will detail the main mechanisms that explain the powerful effect that stress has on substance use. [ABSTRACT FROM AUTHOR]

Background: Selective mutism (SM) has been conceptualized as an extreme variant of social anxiety disorder (SAD), in which the failure to speak functions as an avoidance mechanism leading to a reduction of intense fear arousal. However, psychophysiological studies in children with SM are scarce and physiological mechanisms underlying the failure to speak are largely unknown. In contrast, children with SAD are characterized by a combination of a chronically elevated physiological arousal and a blunted physiological fear response to social stress. Due to the large overlap between SM and SAD, similar mechanisms might apply to both disorders, while differences might explain why children with SM fail to speak. The aim of our study is to investigate psychophysiological mechanisms of the failure to speak in children with SM. Methods: We assessed in a total of N = 96 children [8–12 years, SM: n = 31, SAD: n = 32, typical development (TD): n = 33] resting baseline arousal in absence of social threat and the course of physiological fear response in two social stress paradigms, differing in terms of whether the children are expected to speak (verbal task) or not (nonverbal task). Results: Children with SM were characterized by increased tonic arousal compared to the other two groups, and by a more inflexible stress response in the nonverbal but not in the verbal task compared to TD-children. Further analyses revealed that children with SM who did not speak during the verbal task already demonstrated reduced arousal in anticipation of the verbal task. Conclusion: The increased tonic arousal generalized to non-social situations in SM could indicate a long-term alteration of the autonomic nervous system. Furthermore, the differential physiological stress response may indicate that silence acts as a maladaptive compensatory mechanism reducing stress in verbal social situations, which does not function in nonverbal situations. Our findings support the idea that the failure to speak might function as an avoidance mechanism, which is already active in anticipation of a verbal situation. Treatment of SM should take into account that children with SM may suffer from chronically elevated stress levels and that different mechanisms might operate in verbal and nonverbal social situations. [ABSTRACT FROM AUTHOR]

Introduction: Persons with social anxiety disorder (SAD) often experience social interactions as threatening and commonly avoid them or perform poorly in them (Asher et al., 2017). Self-affirmation is an intervention shown to help individuals engage effectively in situations they perceive as threatening (Sherman & Hartson, 2011). We hypothesized that self-affirmation would allow socially anxious individuals to participate in more social activities, do so more effectively, and with less stress and anxiety. Methods: Following completion of baseline measures, 75 socially anxious university students were randomly assigned to complete a self-affirming or control writing task. They subsequently completed the Trier Social Stress Test for Groups (TSST-G), and received SAD psychoeducation designed to promote social engagement over the coming month, after which they were reassessed on baseline measures of social anxiety. Results Self-affirmation demonstrated no benefit at the time of engagement in the TSST-G. However, at follow-up, self-affirmed students reported significantly less discomfort, anxiety, and distress related to a variety of social behaviors as well as more engagement in those behaviors, relative to baseline, compared with non-affirmed students. Moreover, significantly more affirmed than non-affirmed participants reported clinically significant reductions in symptoms of SAD at follow-up. Discussion These results help to broaden our conceptualization of self-affirmation and provide support for its potential utility in treatment for those with SAD. [ABSTRACT FROM AUTHOR]

Stress and aggression have negative effects on fish welfare and productivity in aquaculture. Thus, research to understand aggression and stress in farmed fish is required. The neuropeptides arginine-vasotocin (AVT) and corticotropin-releasing factor (CRF) are involved in the control of stress and aggression. Therefore, we investigated the effect of agonistic interactions on the gene expression of AVT, CRF and their receptors in juvenile rainbow trout (Oncorhynchus mykiss). The social interactions lead to a clear dominant-subordinate relationship with dominant fish feeding more and being more aggressive. Subordinate fish had an upregulation of the AVT receptor (AVT-R), an upregulation of CRF mRNA levels, and higher plasma cortisol levels. The attenuating effect of AVT on aggression in rainbow trout is proposed to be mediated by AVT-R, and the attenuating effect of the CRF system is proposed to be mediated by CRF. [ABSTRACT FROM AUTHOR]

Social Anxiety Disorder (SAD) is a highly prevalent and debilitating condition. Although effective treatments exist, their success is limited. This narrative review seeks to advance a comprehensive understanding of the types of social threat affecting individuals with SAD from the perspective of two basic biobehavioral systems: affiliation and social-rank. We argue that SAD is associated with vulnerability to events signaling loss of affiliation (exclusion) and of social-rank (defeat). Specifically, we suggest that SAD is characterized by (a) hyper-reactivity to exclusion and defeat; (b) propensity to respond to exclusion by deploying distancing and withdrawal strategies; (c) propensity to respond to defeat by deploying conflict-reducing subordination strategies; and (d) enhanced linkage of the two systems. This dual-system account may help integrate clinically significant information about SAD and offer recommendations regarding novel theory-based directions for treatments.

This article is dedicated to examining the phenomenon of interpersonal political and psychological tension, as well as its measurement in the context of individual hostility and interpersonal sensitivity. The concept of social or interpersonal stress, which is generic in relation to interpersonal political and psychological tension, is analyzed. The article identifies the fragmentation of the field of relevant research, as well as a lack of the standardized sociological tools necessary to study the phenomenon of interpersonal political and psychological tension. The results of three validation studies aimed at developing the sociological test “Interpersonal Political and Psychological Tension” are described. An assessment is made of such parameters of the tool as the distribution of its total values, factor and construct validity, intergroup differences. The first study was a nationwide survey conducted in September 2019 (N = 600). The second study was an online survey conducted in September 2019 (N = 475). The third study was a nationwide survey conducted in February 2020 (N = 2038). A test variant was identified which provides the best results when used in mass surveys. Two patterns of the test’s factorial structure are revealed, one of which is semantic, and the second being methodological in nature. Moreover, in both cases, high indices of factor validity were recorded. In the framework of construct validation, the test indicators appear to be loosely linked to the elements of the nomological network of political culture associated with attitudes. At the same time, a closer connection was observed to behavioral variables which describe individual aspects of everyday political activity. The following conclusions are made: 1) the test for measuring interpersonal political and psychological tension shows acceptable indices of factor and structural validity; 2) the study of the socio-psychological characteristics of political processes appears to be a promising area for further research using the test; 3) the specific composition of this test in the framework of public surveys is crucial for the reliability of its results when using personal interviews.

Exposure of lab animals, humans, and pigs to olfactory sensory feed additives may reduce response to stress and anxiety. The objective of this preliminary study was to determine if feeding a citrus-based olfactory sensory functional feed extract (derived from Citrus sinensis) reduces the negative impact of regrouping of lactating dairy cows. Thirty-two (parity = 2.0 ± 1.2; mean ± SD), mid-lactation Holstein dairy cows (169.8 ± 16.8 DIM) were enrolled as focal cows in this study and housed individually in a tie-stall facility where they were randomly assigned to 1 of 2 treatment diets: (1) control total mixed ration (TMR) (control; n = 16; primiparous = 7; multiparous = 9), or (2) control TMR with 4 g/d of citrus extract (CE) (Phodé, Terssac, France) (CE; n = 16; primiparous = 7; multiparous = 9). Cows were fed their experimental diets for 7 d in the tie-stall facility (baseline), then moved to 1 of 2 experimental free-stall pens (containing 29 other cows) for a period of 7 d, where they remained on the same treatment diet as before. Compared with their baseline, primiparous control cows had decreased rumination time on d 1 and 2, had decreased lying time on d 1, and tended to have decreased lying time on d 2 and 3 following regrouping. In contrast, primiparous cows fed the CE diet did not experience a change in rumination and lying time. Primiparous CE cows had greater feeding time on d 1 and tended to have greater feeding time on d 2 after regrouping compared to primiparous control cows. Primiparous control cows had greater idle standing time, as compared to the CE cows, across the 7 d after regrouping. Primiparous CE cows initiated less total competitive behavior after regrouping, but were also displaced more frequently from the feed bunk and from the free stalls on d 1 after regrouping, as compared to the primiparous control cows. For multiparous cows, CE supplementation was not consistently associated with any benefits to behavior or production after regrouping, possibly because these cows were more experienced with social stressors. Results indicate that feeding CE to mid-lactation naïve primiparous dairy cows may reduce the initiation of competitive interactions and lessen the reduction in rumination and lying time after regrouping. These results need to be verified in further studies where potential confounding effects (e.g., pen social dynamics, pen location) are minimized.

Territoriality, spatial exploration and social hierarchy are strictly related behaviors in gregarious fishes, and are often under-appreciated in farms where the individuals are confined within crowded spaces. In this study, we investigated the role of spatial exploration, elucidating the importance of time upon forming the social organization, and the role of the territoriality in gilthead seabream (Sparus aurata), using two experimental approaches. In the first approach, three fish were placed sequentially in the aquarium with an interval of two days (sequential model), while in the second (simultaneous model), two fish were simultaneously placed in an aquarium divided by a barrier which was removed after a certain period of time. To study the effect of social stress and spatial perception in the two models, we monitored behavior (aggressive acts and feeding priority), integrated with the evaluation of physiological and cellular stress parameters, such as phagocytosis, cortisol, glucose, and blood osmolarity levels. After the establishment of the social hierarchy in the “sequential model”, we observed that the levels of cortisol and an immunological cell-mediated marker were higher in subordinate individuals than in the dominant ones. We observed a different modulation of phagocytic activity in peritoneal cavity cells between dominant and subordinates, demonstrating that social stress acts upon immune response. Differently from the first model, no behavioral, physiological, or phagocytic differences were found between the two fish involved in the simultaneous model, where both fish acted as co-dominants, defending their territory. The study achieved a deeper understanding of the role of spatial exploration, territorial dominance and intraspecific interaction in gilthead seabream, and elucidated the link between them and physiological stress indicators. The results highlight aspects of interest to the aquaculture industry, showing the importance of a greater focus on rearing conditions, finding solutions to mitigate crowding effects and promoting the quality of aquacultural products.

Stress is a critical factor in the development of mood and drug use disorders. The social defeat model is not appropriate for female rodents due to their low level of aggression. Therefore, a robust female model of social stress needs to be developed and validated. The aim of the present study was to unravel the long-lasting effects of vicarious social defeat (VSD) on the conditioned rewarding effects of cocaine and ethanol intake in female mice. Although VSD seems to be a good model for inducing behavioral and physiologic endophenotypes induced by stress, there are no studies to date that characterize the effect of VSD on cocaine or alcohol use. The results confirm that VSD females showed an increase in corticosterone levels after a vicarious experience while also displaying an increase in anxiety- and anhedonic-like behaviors. Three weeks after the last VSD, vicariously defeated female mice showed an increased developed preference for a non-effective dose of cocaine in the conditioned place preference (CPP) paradigm and showed an increase in ethanol intake. Our results suggest that female mice vicariously experience a state of distress through the social observation of others suffering from adverse events, confirming the use of VSD as a valid model to study the response to social stress in females. The fact that VSD in females induced a comparable behavioral phenotype to that observed in physically defeated males could indicate a relationship with the higher rate of psychopathologies observed in women. Notwithstanding, more studies are needed to dissect the neurobiological and behavioral peculiarities of the female response to social stress.

Background and Objectives: CDC data indicate that the U.S. is experiencing a sustained epidemic of drug-related mortality, with such deaths exceeding a record 100,000 in 2021, up 47% from 2019. Opioids, especially the synthetic opioid fentanyl, account for approximately 75% of this mortality. This study evaluates a proposed Consciousness-Based® approach that may possibly help reduce trends in drug-related fatalities by mitigating what WHO refers to as an “epidemic of stress” in society that helps fuel drug misuse and other negative public health trends. This approach involves providing support in public and private sector public health initiatives for individual and group practice of a subjective, evidence-based meditation procedure suitable for those of all educational, cultural, and religious backgrounds: the Transcendental Meditation® (TM®) technique and its advanced aspect, the TM-Sidhi® program. Materials and Methods: Segmented-trend regression analysis of monthly CDC data on U.S. drug-related fatality rates (dfr) from a prospective social experiment (2002–2016) was used to replicate and extend prior peer-reviewed research. Results: As hypothesized, (1) practice of the TM and TM-Sidhi program by a group of theoretically predicted size (√1% of the U.S. population) was associated with a statistically and practically significant reduction in dfr trend during the five-year “demonstration period” of the quasi-experiment; and (2) monthly dfr trend subsequently increased during the five-year follow-up period when the group fell below the required size (both p’s < 0.0001). The estimated total percent decrease in dfr during the demonstration period was 35.5%, calculated relative to the baseline mean. This decline was followed by total dfr increases of 11.8% and 47.4% relative to the demonstration-period mean during the two phases of the follow-up period. Conclusion: Existing evidence warrants implementation and further evaluation of this approach in U.S. public health initiatives.

Social animals enjoy colony benefits but are also exposed to social stress, which affects their physiology in many ways, including alterations to their energy intake, metabolism, and even gene expression. Aggressive calls are defined as calls emitted during aggressive conflicts between individuals of the same species over resources, such as territory, food, or mates. Aggressive calls produced by animals in different aggressive states indicate different levels of competitive intentions. However, whether aggressive calls produced in different aggressive states exert different physiological effects on animals has yet to be determined. Importantly, bats live in clusters and frequently produce aggressive calls of different syllables, thus providing an ideal model for investigating this question. Here, we conducted playback experiments to investigate the effects of two types of aggressive calls representing different competitive intentions on food intake, body mass, corticosterone (CORT) concentration, and gene expression in Vespertilio sinensis. We found that the playback of both aggressive calls resulted in a significant decrease in food intake and body mass, and bats in the tonal-syllable aggressive-calls (tonal calls) playback group exhibited a more significant decrease when compared to the noisy-syllable aggressive-calls (noisy calls) playback group. Surprisingly, the weight and food intake in the white-noise group decreased the most when compared to before playback. Transcriptome results showed that, when compared to the control and white-noise groups, differentially expressed genes (DEGs) involved in energy and metabolism were detected in the noisy-calls playback group, and DEGs involved in immunity and disease were detected in the tonal-calls playback group. These results suggested that the playback of the two types of aggressive calls differentially affected body mass, food intake, and gene expression in bats. Notably, bat responses to external-noise playback (synthetic white noise) were more pronounced than the playback of the two aggressive calls, suggesting that bats have somewhat adapted to internal aggressive calls. Comparative transcriptome analysis suggested that the playback of the two syllabic aggressive calls disrupted the immune system and increased the risk of disease in bats. This study provides new insight into how animals differ in response to different social stressors and anthropogenic noise.

Social species form organizations that support individuals because the consequent social behaviors help these organisms survive. The isolation of these individuals may be a stressor. We reviewed the potential mechanisms of the effects of social isolation on cholinergic signaling and vice versa how changes in cholinergic signaling affect changes due to social isolation.There are two important problems regarding this topic. First, isolation schemes differ in their duration (1–165 days) and initiation (immediately after birth to adulthood). Second, there is an important problem that is generally not considered when studying the role of the cholinergic system in neurobehavioral correlates: muscarinic and nicotinic receptor subtypes do not differ sufficiently in their affinity for orthosteric site agonists and antagonists. Some potential cholinesterase inhibitors also affect other targets, such as receptors or other neurotransmitter systems. Therefore, the role of the cholinergic system in social isolation should be carefully considered, and multiple receptor systems may be involved in the central nervous system response, although some subtypes are involved in specific functions. To determine the role of a specific receptor subtype, the presence of a specific subtype in the central nervous system should be determined using search in knockout studies with the careful application of specific agonists/antagonists. [ABSTRACT FROM AUTHOR]