Boiling over Kennedy, Ann
Science (American Association for the Advancement of Science),
11/2022, Volume:
378, Issue:
6619
Journal Article
Peer reviewed
An emergent encoding of aggressive motivation in neurons of the hypothalamus
Aggression between members of a species takes many forms, but the rule-book that guides it is ancient. Fighting may help ...resources and mates go to the fittest members of a species, as Darwin posed ( 1 ). This aggression can also serve as a repelling force to distribute animals evenly over an environment ( 2 ). In social species, aggression creates hierarchies that shape the health and behavior of group members ( 3 ). But picking a fight is costly because even the winner may walk away with injuries. If time allows, it is safer to begin with threat displays and posturing and only escalate to outright attack if neither side will back down ( 4 ).
Although the hippocampus is known to be important for declarative memory, it is less clear how hippocampal output regulates motivated behaviours, such as social aggression. Here we report that ...pyramidal neurons in the CA2 region of the hippocampus, which are important for social memory, promote social aggression in mice. This action depends on output from CA2 to the lateral septum, which is selectively enhanced immediately before an attack. Activation of the lateral septum by CA2 recruits a circuit that disinhibits a subnucleus of the ventromedial hypothalamus that is known to trigger attack. The social hormone arginine vasopressin enhances social aggression by acting on arginine vasopressin 1b receptors on CA2 presynaptic terminals in the lateral septum to facilitate excitatory synaptic transmission. In this manner, release of arginine vasopressin in the lateral septum, driven by an animal's internal state, may serve as a modulatory control that determines whether CA2 activity leads to declarative memory of a social encounter and/or promotes motivated social aggression.
There is an important relationship between the immune system and aggressive behavior. Aggressive encounters acutely increase the levels of proinflammatory cytokines, and there are positive ...correlations between aggressive traits and peripheral proinflammatory cytokines. Endotoxin lipopolysaccharide (LPS) treatment, which results in peripheral immune activation, decreases aggressive behavior as one of the sickness behavioral symptoms. In contrast, certain brain infections and chronic interferon treatment are associated with increased aggression. Indeed, the effects of proinflammatory cytokines on the brain in aggressive behavior are bidirectional, depending on the type and dose of cytokine, target brain region, and type of aggression. Some studies have suggested that microglial activation and neuroinflammation influence intermale aggression in rodent models. In addition, pathological conditions as well as physiological levels of cytokines produced by microglia play an important role in social and aggressive behavior in adult animals. Furthermore, microglial function in early development is necessary for the establishment of the social brain and the expression of juvenile social behaviors, including play fighting. Overall, this review discusses the important link between the immune system and aggressive traits and the role of microglia as mediators of this link.
Heterogeneity of cytokine/microglial involvement in aggressive behavior. CC: cingulate cortex, HIP: hippocampus, DRN: dorsal raphe nucleus, PAG: periaqueductal grey, MH: medial hypothalamus. Display omitted
•Proinflammatory cytokines have bidirectional effects in aggressive behavior.•Both neuroinflammation and physiological levels of cytokines produced by microglia influence aggressive behavior.•Microglial function during early development is necessary for juvenile social behavior including play fighting.
There is limited evidence for the association among soft drink consumption, aggressive behaviors, and depressive symptoms among the adolescents.
Data were derived from a national representative ...sample of Youth Risk Behavior Surveys of United States during 2011 to 2019. Binary logistic regression models with complex sampling design were used to estimate the effect of soft drink consumption on aggressive behaviors and depressive symptoms. Mediating analysis was used to explore the association between soft drink consumption and depressive symptoms by aggressive behaviors.
The total prevalence of depressive symptoms was 3l.2 % (30.3 %–32.0 %). Compared with none of soft drink consumption, <1 time/day (OR: 1.29, 95%CI: 1.19–1.41), 1–2 times/day (OR: 1.49, 95%CI: 1.33–1.67), and ≥3 times/day (OR: 1.95, 95%CI: 1.70–2.24) were significantly associated with increased risk of aggressive behaviors. High levels of soft drink consumption (1–2 times/day, OR: 1.19, 95%CI: 1.07–1.32; ≥3 times/day, OR: 1.61, 95%CI: 1.42–1.81) and aggressive behaviors (OR: 1.98, 95%CI: 1.84–2.13) were found to be significantly associated with increased risk of depressive symptoms. A linear dose-response relationship of soft drink consumption with aggressive behaviors and depressive symptoms was found in this study (all p < 0.001). Aggressive behaviors partially mediated the association between soft drink consumption and depressive symptoms and each pathway was statistically significant.
The causal relationship was not able to certain because of the cross-sectional design.
The mediating role of aggressive behaviors on the association of high levels of soft drink consumptions with depressive symptoms should be paid more attention among the adolescents.
•Aggressive behaviors mediated the association between soft drink consumption and depressive symptoms among the adolescents.•A linear dose-response relationship of soft drink consumption with aggressive behaviors and depressive symptoms was found.•Sex- and age-specific relationship of soft drink consumption with aggressive behaviors and depressive symptoms were reported.
This study aims to examine the mediating role of self-efficacy (SE) and self-control (SC) in the relationship between physical activity (PA) and aggressive behaviors (AB) among college students. It ...provides a basis for the prevention and control of AB among college students. This study employed a survey research methodology, including the PA Level Scale, the General Self-efficacy Scale, the Self-control Scale, and the Chinese Aggressive Behaviors Scale on 950 college students. The chain mediating effect test and Bootstrap analysis were applied. The results were as follows: (1) There was a main effect of PA on SE, SC, and AB as well as all sub-indicators (physical aggression, verbal aggression, anger, hostility, self-directed aggression), i.e., PA had a direct effect on the control of all three; (2) PA level was significantly negatively correlated with AB and significantly positively correlated with SE and SC. That is, the higher the level of PA, the better the SE and SC, and the lower the probability of AB; (3) The three pathways had mediating effects: PA → SE → AB, PA → SC → AB, PA → SE → SC → AB, with effect sizes of 8.78%, 28.63%, and 19.08%, respectively. It is concluded that regular PA is a potent method for decreasing aggressive behavior and psychological issues in university students while additionally promoting self-efficacy and self-control. Increasing the intensity of PA may enhance the effectiveness of these chain benefits.
Fishes show remarkably diverse aggressive behaviour. Aggression is expressed to secure resources; adjusting aggression levels according to context is key to avoid negative consequences for fitness ...and survival. Nonetheless, despite its importance, the physiological basis of aggression in fishes is still poorly understood. Several reports suggest hormonal modulation of aggression, particularly by androgens, but contradictory studies have been published. Studies exploring the role of chemical communication in aggressive behaviour are also scant, and the pheromones involved remain to be unequivocally characterized. This is surprising as chemical communication is the most ancient form of information exchange and plays a variety of other roles in fishes. Furthermore, the study of chemical communication and aggression is relevant at the evolutionary, ecological and economic levels. A few pioneering studies support the hypothesis that aggressive behaviour, at least in some teleosts, is modulated by “dominance pheromones” that reflect the social status of the sender, but there is little information on the identity of the compounds involved. This review aims to provide a global view of aggressive behaviour in fishes and its underlying physiological mechanisms including the involvement of chemical communication, and discusses the potential use of dominance pheromones to improve fish welfare. Methodological considerations and future research directions are also outlined.
This meta-analytic review examines the link between narcissism and aggression, and whether the link is stronger under provocation conditions. A total of 437 independent studies were located, which ...included 123,043 participants. Narcissism was related to both aggression (r = .26, .24, .28) and violence (r = .23, .18, .27). As expected, the narcissism-aggression link was stronger under provocation conditions (r = .29, .23, .36) than under no provocation conditions (r = .12, .05, .18), but was even significant in the absence of provocation. Both "normal" and "pathological" narcissism were related to aggression. All three dimensions of narcissism (i.e., entitlement, grandiose narcissism, vulnerable narcissism) were related to aggression. Narcissism was related to all forms of aggression (i.e., indirect, direct, displaced, physical, verbal, bullying), and to both functions of aggression (i.e., reactive, proactive). The relation between narcissism and aggression was significant for males and females, for people of all ages, for students and nonstudents, and for people from individualistic and collectivistic countries. Significant results were obtained in experimental, cross-sectional, and longitudinal studies, in published and unpublished studies, and in studies that assessed aggression using different types of measures (i.e., self-report, other-report, observation). Overall results were robust to publication bias and the presence of outliers. Theoretically, these results indicate that provocation is a key moderator of the link between narcissism and aggression. Individuals high in narcissism have "thin skins" and are prone to aggression when they are provoked. Practically, these results suggest that narcissism is an important risk factor for aggression and violence.
Public Significance StatementThis meta-analytic review found that individuals with high levels of narcissism are prone to aggressive and violent behavior, especially when they are provoked. There was a triangulation of results across different research methodologies. The relationship was robust for different forms and functions of aggression, different types and dimensions of narcissism, and for males and females of different ages from different countries.
Aggression and violence against educators and school personnel have raised public health concerns that require attention from researchers, policymakers, and training providers in U.S. schools. School ...aggression and violence have negative effects on school personnel health and retention and on student achievement and development. In partnership with several national organizations, the American Psychological Association (APA) Task Force on Violence Against Educators and School Personnel administered two national, multi-informant, cross-sectional surveys. Time 1 data were collected in 2020-2021 from 14,966 respondents; participants reflected on their experiences of violence and aggression before COVID-19 and during COVID-19 restrictions in this survey. One year later, in 2022, 11,814 respondents completed the Time 2 survey after COVID-19 restrictions ended. Participants included teachers, school psychologists, social workers, counselors, staff members, and administrators from all 50 states and Puerto Rico. Rates of violence and aggression directed against educators by students, parents, colleagues, and administrators were substantial before COVID-19, were lower during COVID-19 restrictions, and returned to prepandemic levels or higher after COVID-19 restrictions. After COVID-19 restrictions, 22%-80% of respondents reported verbal or threatening aggression, and 2%-56% of respondents reported physical violence at least once during the year, varying by stakeholder role and aggressor. Rates of intentions to quit the profession ranged from 21% to 43% during COVID-19 restrictions (2020-2021) and from 23% to 57% after COVID-19 restrictions (2021-2022), varying by stakeholder role. Participants across roles reported substantial rates of anxiety and stress, especially during and after COVID-19 restrictions, and identified specific training needs. Implications for theory, research, training, and policy are presented. (PsycInfo Database Record (c) 2024 APA, all rights reserved).
Objective: The purpose of this study was to investigate gene/protein expression alterations of intercellular connections' components in oral leukoplakia (OLs) and squamous-cell carcinoma (OSCCs). ...Materials and methods: Expression of desmogleins-2,3 (Dsg2/Dsg3), E-cadherin, and their cytoplasmic ligand, beta / gamma -catenins were quantitatively assessed in HSC-3 cells growing as monolayer cultures (ML)/multicellular aggregates (MCAs), using RT-PCR/Western blot, whereas their localization was detected by immunofluorescence. Furthermore, their expression was semi-quantitatively investigated in tissues from 25 OLs/25 OSCCs, using automated immunohistochemistry. Results: The steady-state levels of Dsg3 RNA transcripts increased as HSC-3 cells enter their exponential phase of growth, before a dramatic decrease to be observed as cells reached their plateau phase especially in MCAs. Upon the same period of time, Dsg2 levels have been increased. The expression of gamma -catenin but not that of beta -catenin was increased after 48 h in both MLs and MCAs. In clinical samples, Dsg3, epsilon -cadherin, beta / gamma -catenin down-regulation was observed to be associated with the grade of OLs-dysplasia and OSCCs. Importantly, a membrane-to-cytoplasmic switch of expression and strong perinuclear aggregation of Dsg3/ gamma -catenin was seen in both HSC-3 cells and OLs/OSCCs. Conclusions: The altered expression of Dsg3/ gamma -catenin and E-cadherin/ beta -catenin, in vitro and in ODs/OSCC imply their involvement in growth regulation and phenotype of dysplastic/malignant oral epithelial cells, contributing to the better understanding of epithelial dysplasia and OSCCs. Clinical relevance: The observed alterations of their expression suggest a role of Dsg3 and gamma -catenin (additionally to E-cadherin/ beta -catenin) as biomarkers of malignant transformation risk of oral dysplasia and the biological behavior (aggressiveness) of oral cancer, respectively.
PDF
