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Cell Mar 2023Social interactions require awareness and understanding of the behavior of others. Mirror neurons, cells representing an action by self and others, have been proposed to...
Social interactions require awareness and understanding of the behavior of others. Mirror neurons, cells representing an action by self and others, have been proposed to be integral to the cognitive substrates that enable such awareness and understanding. Mirror neurons of the primate neocortex represent skilled motor tasks, but it is unclear if they are critical for the actions they embody, enable social behaviors, or exist in non-cortical regions. We demonstrate that the activity of individual VMHvl neurons in the mouse hypothalamus represents aggression performed by self and others. We used a genetically encoded mirror-TRAP strategy to functionally interrogate these aggression-mirroring neurons. We find that their activity is essential for fighting and that forced activation of these cells triggers aggressive displays by mice, even toward their mirror image. Together, we have discovered a mirroring center in an evolutionarily ancient region that provides a subcortical cognitive substrate essential for a social behavior.
Topics: Animals; Mice; Aggression; Hypothalamus; Mirror Neurons; Social Behavior
PubMed: 36796363
DOI: 10.1016/j.cell.2023.01.022 -
PloS One 2021On psychiatric wards, aggressive behaviour displayed by patients is common and problematic. Understanding factors associated with the development of aggression offers...
INTRODUCTION
On psychiatric wards, aggressive behaviour displayed by patients is common and problematic. Understanding factors associated with the development of aggression offers possibilities for prevention and targeted interventions. This review discusses factors that contribute to the development of aggression on psychiatric wards.
METHOD
In Pubmed and Embase, a search was performed aimed at: prevalence data, ward characteristics, patient and staff factors that are associated with aggressive behaviour and from this search 146 studies were included.
RESULTS
The prevalence of aggressive behaviour on psychiatric wards varied (8-76%). Explanatory factors of aggressive behaviour were subdivided into patient, staff and ward factors. Patient risk factors were diagnosis of psychotic disorder or bipolar disorder, substance abuse, a history of aggression, younger age. Staff risk factors included male gender, unqualified or temporary staff, job strain, dissatisfaction with the job or management, burn-out and quality of the interaction between patients and staff. Staff protective factors were a good functioning team, good leadership and being involved in treatment decisions. Significant ward risk factors were a higher bed occupancy, busy places on the ward, walking rounds, an unsafe environment, a restrictive environment, lack of structure in the day, smoking and lack of privacy.
CONCLUSION
Despite a lack of prospective quantitative data, results did show that aggression arises from a combination of patient factors, staff factors and ward factors. Patient factors were studied most often, however, besides treatment, offering the least possibilities in prevention of aggression development. Future studies should focus more on the earlier stages of aggression such as agitation and on factors that are better suited for preventing aggression such as ward and staff factors. Management and clinicians could adapt staffing and ward in line with these results.
Topics: Aggression; Bed Occupancy; Female; Health Personnel; Humans; Male; Mental Health; Prevalence; Psychiatric Department, Hospital; Risk Factors; Substance-Related Disorders; Time Factors; Violence
PubMed: 34624057
DOI: 10.1371/journal.pone.0258346 -
Cell Jan 2023The hypothalamus regulates innate social behaviors, including mating and aggression. These behaviors can be evoked by optogenetic stimulation of specific neuronal...
The hypothalamus regulates innate social behaviors, including mating and aggression. These behaviors can be evoked by optogenetic stimulation of specific neuronal subpopulations within MPOA and VMHvl, respectively. Here, we perform dynamical systems modeling of population neuronal activity in these nuclei during social behaviors. In VMHvl, unsupervised analysis identified a dominant dimension of neural activity with a large time constant (>50 s), generating an approximate line attractor in neural state space. Progression of the neural trajectory along this attractor was correlated with an escalation of agonistic behavior, suggesting that it may encode a scalable state of aggressiveness. Consistent with this, individual differences in the magnitude of the integration dimension time constant were strongly correlated with differences in aggressiveness. In contrast, approximate line attractors were not observed in MPOA during mating; instead, neurons with fast dynamics were tuned to specific actions. Thus, different hypothalamic nuclei employ distinct neural population codes to represent similar social behaviors.
Topics: Animals; Sexual Behavior, Animal; Ventromedial Hypothalamic Nucleus; Hypothalamus; Aggression; Social Behavior
PubMed: 36608653
DOI: 10.1016/j.cell.2022.11.027 -
Social Neuroscience Aug 2022Aggression occurs frequently and severely between rival groups. Although there has been much study into the psychological and socio-ecological determinants of intergroup...
Aggression occurs frequently and severely between rival groups. Although there has been much study into the psychological and socio-ecological determinants of intergroup aggression, the neuroscience of this phenomenon remains incomplete. To examine the neural correlates of aggression directed at outgroup (versus ingroup) targets, we recruited 35 healthy young male participants who were current or former students of the same university. While undergoing functional MRI, participants completed an aggression task against both an ingroup and an outgroup opponent in which their opponents repeatedly provoked them at varying levels and then participants could retaliate. Participants were then socially included and then excluded by two outgroup members and then completed the same aggression task against the same two opponents. Both before and after outgroup exclusion, aggression toward outgroup members was positively associated with activity in the ventral striatum during decisions about how aggressive to be toward their outgroup opponent. Aggression toward outgroup members was also linked to greater post-exclusion activity in the rostral and dorsal medial prefrontal cortex during provocation from their outgroup opponent. These altered patterns of brain activity suggest that frontostriatal mechanisms may play a significant role in motivating aggression toward outgroup members.
Topics: Aggression; Humans; Magnetic Resonance Imaging; Male; Prefrontal Cortex; Ventral Striatum
PubMed: 35658812
DOI: 10.1080/17470919.2022.2086617 -
Journal of Child and Adolescent... Oct 2019Aggressive behavior is among the most common reasons for referral to psychiatric clinics and confers significant burden on individuals. Aggression remains poorly... (Review)
Review
Aggressive behavior is among the most common reasons for referral to psychiatric clinics and confers significant burden on individuals. Aggression remains poorly defined; there is currently no consensus on the best ways to recognize, diagnose, and treat aggression in clinical settings. In this review, we synthesize the available literature on aggression in children and adolescents and propose the concept of impulsive aggression (IA) as an important construct associated with diverse and enduring psychopathology. Articles were identified and screened from online repositories, including PubMed, PsychInfo, the Cochrane Database, EMBase, and relevant book chapters, using combinations of search terms such as "aggression," "aggressive behavio(u)r," "maladaptive aggression," "juvenile," and "developmental trajectory." These were evaluated for quality of research before being incorporated into the article. The final report references 142 sources, published from 1987 to 2019. Aggression can be either adaptive or maladaptive in nature, and the latter may require psychosocial and biomedical interventions when it occurs in the context of central nervous system psychopathology. Aggression can be categorized into various subtypes, including reactive/proactive, overt/covert, relational, and IA. IA in psychiatric or neurological disorders is reviewed along with current treatments, and an algorithm for systematic evaluation of aggression in the clinical setting is proposed. IA is a treatable form of maladaptive aggression that is distinct from other aggression subtypes. It occurs across diverse psychiatric and neurological diagnoses and affects a substantial subpopulation. IA can serve as an important construct in clinical practice and has considerable potential to advance research.
Topics: Adolescent; Aggression; Child; Humans; Impulsive Behavior; Mental Disorders
PubMed: 31453715
DOI: 10.1089/cap.2019.0039 -
Journal of Child and Adolescent... Feb 2016This selective review provides a model of the neurobiology of impulsive aggression from a cognitive neuroscience perspective. It is argued that prototypical cases of... (Review)
Review
This selective review provides a model of the neurobiology of impulsive aggression from a cognitive neuroscience perspective. It is argued that prototypical cases of impulsive aggression, those associated with anger, involve the recruitment of the acute threat response system structures; that is, the amygdala, hypothalamus, and periaqueductal gray. It is argued that whether the recruitment of these structures results in impulsive aggression or not reflects the functional roles of ventromedial frontal cortex and dorsomedial frontal and anterior insula cortex in response selection. It is also argued that impulsive aggression may occur because of impaired decision making. The aggression may not be accompanied by anger, but it will reflect disrupted evaluation of the rewards/benefits of the action.
Topics: Aggression; Brain; Humans; Impulsive Behavior; Neurobiology
PubMed: 26465707
DOI: 10.1089/cap.2015.0088 -
Aggressive Behavior May 2023Parent and child endorsement of reactive aggression both predict the emergence of child aggression, but they are rarely studied together and in longitudinal contexts....
Parent and child endorsement of reactive aggression both predict the emergence of child aggression, but they are rarely studied together and in longitudinal contexts. The present study does so by examining the unique predictive effects of parent and child endorsement of reactive aggression at age 8 on child aggression at age 9 in 1456 children from 13 cultural groups in 9 nations. Multiple group structural equation models explored whether age 8 child and parent endorsement of reactive aggression predicted subsequent age 9 child endorsement of reactive aggression and child aggression, after accounting for prior child aggression and parent education. Results revealed that greater parent endorsement of reactive aggression at age 8 predicted greater child endorsement of aggression at age 9, that greater parent endorsement of reactive aggression at age 8 uniquely predicted greater aggression at age 9 in girls, and that greater child endorsement of reactive aggression at age 8 uniquely predicted greater aggression at age 9 in boys. All three of these associations emerged across cultures. Implications of, and explanations for, study findings are discussed.
Topics: Aggression; Internationality; Culture; Parents; Humans; Child; Child Behavior; Male; Female; Parent-Child Relations; Cross-Cultural Comparison
PubMed: 36565473
DOI: 10.1002/ab.22067 -
Journal of Experimental Zoology. Part... Dec 2022Individuals of virtually all vertebrate species are exposed to annual fluctuations in the deterioration and renewal of their environments. As such, organisms have... (Review)
Review
Individuals of virtually all vertebrate species are exposed to annual fluctuations in the deterioration and renewal of their environments. As such, organisms have evolved to restrict energetically expensive processes and activities to a specific time of the year. Thus, the precise timing of physiology and behavior is critical for individual reproductive success and subsequent fitness. Although the majority of research on seasonality has focused on seasonal reproduction, pronounced fluctuations in other non-reproductive social behaviors, including agonistic behaviors (e.g., aggression), also occur. To date, most studies that have investigated the neuroendocrine mechanisms underlying seasonal aggression have focused on the role of photoperiod (i.e., day length); prior findings have demonstrated that some seasonally breeding species housed in short "winter-like" photoperiods display increased aggression compared with those housed in long "summer-like" photoperiods, despite inhibited reproduction and low gonadal steroid levels. While fewer studies have examined how the hormonal correlates of environmental cues regulate seasonal aggression, our previous work suggests that the pineal hormone melatonin acts to increase non-breeding aggression in Siberian hamsters (Phodopus sungorus) by altering steroid hormone secretion. This review addresses the physiological and cellular mechanisms underlying seasonal plasticity in aggressive and non-aggressive social behaviors, including a key role for melatonin in facilitating a "neuroendocrine switch" to alternative physiological mechanisms of aggression across the annual cycle. Collectively, these studies highlight novel and important mechanisms by which melatonin regulates aggressive behavior in vertebrates and provide a more comprehensive understanding of the neuroendocrine bases of seasonal social behaviors broadly.
Topics: Cricetinae; Animals; Melatonin; Seasons; Phodopus; Aggression; Photoperiod
PubMed: 35451566
DOI: 10.1002/jez.2601 -
Pharmacology, Biochemistry, and Behavior Nov 2017Inter-male aggression is an essential component of social behavior in organisms from insects to humans. However, when expressed inappropriately, aggression poses... (Review)
Review
Inter-male aggression is an essential component of social behavior in organisms from insects to humans. However, when expressed inappropriately, aggression poses significant threats to the mental and physical health of both the aggressor and the target. Inappropriate aggression is a common feature of numerous neuropsychiatric disorders in humans and has been hypothesized to result from the atypical activation of reward circuitry in response to social targets. The lateral habenula (LHb) has recently been identified as a major node of the classical reward circuitry and inhibits the release of dopamine from the midbrain to signal negative valence. Here, we discuss the evidence linking LHb function to aggression and its valence, arguing that strong LHb outputs to the ventral tegmental area (VTA) and the dorsal raphe nucleus (DRN) are likely to play roles in aggression and its rewarding components. Future studies should aim to elucidate how various inputs and outputs of the LHb shape motivation and reward in the context of aggression.
Topics: Aggression; Animals; Dopamine; Habenula; Humans; Nerve Net; Neural Pathways; Social Behavior
PubMed: 28499809
DOI: 10.1016/j.pbb.2017.05.003 -
PeerJ 2022Aggressive interactions help individuals to gain access to and defend resources, but they can be costly, leading to increased predation risk, injury, or death. Signals... (Review)
Review
Aggressive interactions help individuals to gain access to and defend resources, but they can be costly, leading to increased predation risk, injury, or death. Signals involving sounds and color can allow birds to avoid the costs of intraspecific aggressive encounters, but we know less about agonistic signaling between species, where fights can be frequent and just as costly. Here, we review photographic and video evidence of aggressive interactions among species of birds ( = 337 interactions documenting the aggressive signals of 164 different bird species from 120 genera, 50 families, and 24 orders) to document how individuals signal in aggressive encounters among species, and explore whether these visual signals are similar to those used in aggressive encounters with conspecifics. Despite the diversity of birds examined, most aggressively signaling birds displayed weapons (bills, talons, wings) used in fighting and placed these weapons closest to their heterospecific opponent when signaling. Most species oriented their bodies and heads forward with their bills pointing towards their heterospecific opponent, often highlighting their face, throat, mouth, and bill. Many birds also opened their wings and/or tails, increasing their apparent size in displays, consistent with the importance of body size in determining behavioral dominance among species. Aggressive postures were often similar across species and taxonomic families. Exceptions included Accipitridae and Falconidae, which often highlighted their talons in the air, Columbidae, which often highlighted their underwings from the side, and Trochilidae, which often hovered upright in the air and pointed their fanned tail downward. Most species highlighted bright carotenoid-based colors in their signals, but highlighted colors varied across species and often involved multiple colors in combination (., black, white, and carotenoid-based colors). Finally, birds tended to use the same visual signals in aggressive encounters with heterospecifics that they use in aggressive encounters with conspecifics, suggesting that selection from aggressive interactions may act on the same signaling traits regardless of competitor identity.
Topics: Humans; Animals; Aggression; Phenotype; Columbidae; Carotenoids
PubMed: 35722268
DOI: 10.7717/peerj.13431