Neural and Hormonal Mechanisms in Aggression

10 Key excerpts on "Neural and Hormonal Mechanisms in Aggression"

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  Handbook of Neuroendocrinology

  • George Fink, Donald W. Pfaff, Jon Levine(Authors)
  • 2011(Publication Date)
  • Academic Press

    (Publisher)

  Chapter 22. Neuroendocrinology of Aggression

  Brian C. Trainor1 and Randy J. Nelson2

  1 Department of Psychology, University of California, Davis, CA, USA

  2 Departments of Neuroscience and Psychology, Ohio State University, Columbus, OH, USA

  Outline

  Introduction509

  Neural Circuits of Aggression510

  Effects of Steroids on Aggressive Behavior510

  Androgens510

  Estrogens512

  Neurosteroids512

  DHEA514

  DHEA514

  Glucocorticoids515

  Effects of Protein and Peptide Hormones on Aggressive Behavior516

  Vasopressin516

  Oxytocin516

  Prolactin516

  Conclusions516

  Summary

  Aggressive behaviors are often assumed to be regulated by testosterone. However, after a century of research it is becoming clear that there is a complex network of neuroendocrine pathways that can regulate aggressive behaviors. This network of steroid and peptide hormones allows for aggressive behaviors to be modified in response seasonal, reproductive and social information. We review the effects of steroids (gonadal, adrenal and neurosteroids) and neuropeptide hormones on aggressive behaviors. Many of these hormones only exert an effect on behavior within a defined environmental context, and we explore the complex interactions between hormones, the environment and behavior. Studies of the neuroendocrine bases of aggressive behavior have provided important insights into how complex behaviors are regulated by hormones. These discoveries may also eventually lead to practical applications, as dysregulated aggression is a component of several mental disorders.

  Introduction

  Neuroendocrinology is the interaction between the nervous and endocrine systems. Traditionally, this field has relied on behavioral changes as the “read-out” in response to manipulations of endocrine signals. Aggressive behaviors have been a focus of many neuroendocrine studies for a variety of reasons, including sex differences in aggression, increased aggression at puberty, and coincidence of aggression with the onset of the breeding season. Males are more aggressive than females in most vertebrate species (although exceptions have been reported), and aggression is associated with the breeding season (again with some notable exceptions, detailed below). Indeed, in the first documented neuroendocrine experiment, Professor Arnold Adolph Berthold, at the University of Göttingen, demonstrated experimentally that a product of the testes was necessary for young roosters to develop typical mating, vocalizing and aggressive behaviors in adulthood. 1

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  Sexual Offender Treatment

  Biopsychosocial Perspectives

  • Edmond J Coleman, Michael Miner(Authors)
  • 2014(Publication Date)
  • Routledge

    (Publisher)

  In animals several categories of aggressive behavior can be identified such as offensive, defensive, predatory, fear-induced, territorial, irritable, sex-related and maternal aggression (Albert, Walch & Jonik, 1993). It is an unresolved question whether all these categories have distinct neurological and hormonal systems underlying their biological execution and what the counterparts are in the human. This question is of interest since a thorough understanding would allow to identify biological predispositions to (sexual) aggression and violence. A better understanding of the neurobiology of (sexual) aggression in terms of neurotransmitters and hormones would allow the development of pharmacological treatment modalities. Together with other treatment strategies (psychological treatment, social rehabilitation), this could help individuals to control their aggressive impulses and to help them to lead more meaningful lives with respect of the rights of their fellow human beings.

  This contribution will address three areas of biological research, which have links with the biology of (sexual aggression):

  1. Androgen-related (sexual) aggression. The role and importance of androgens is often misconceptualized, This contribution will argue that androgens as such show no consistent relation with aggression. Its main function is to lower the threshold for sexual events to occur. If sexual events are of an aggressive nature in an individual's life, they may become better amenable with pharmacological intervention reducing the biological effects of androgens.
  2. Aggression may be related to anatomical or functional disorders of certain brain areas.
  3. Aggression as a stress response disorder. A fascinating area of research is the psychoneuroendocrine substrate of stress. There have been major advances over the last decades. The biological systems of human beings and animals alike, are not closed systems; there is an interaction with the environment. Every internal and external stimulus is interpreted and assessed. Life exists by maintaining a complex dynamic equilibrium, or homeostasis, that is constantly challenged by extrinsic and intrinsic adverse forces (Stratakis & Chrousos, 1994). The organism reacts to this threatened homeostasis with the activation of a complex of behavioral responses evoking fright, flight or fight as defense mechanisms, to preserve integrity. This contribution argues that aggression and violence are maladaptive response mechanisms in reaction to intrinsic and extrinsic stimuli of a system that in essence is designed to confer protection to an organism.

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  Aggression and Violence

  Genetic, Neurobiological, and Biosocial Perspectives

  • David M. Stoff, Robert B. Cairns(Authors)
  • 2014(Publication Date)
  • Psychology Press

    (Publisher)

  Fig. 13.1 . In those instances when both biological and behavioral processes described or explained a developmental process, the integration tended to be deterministic: Biology determines behavior. In the case of aggression, the androgen testosterone (T), for instance, tended to be viewed as a causal agent in aggressive behavior. Recent discoveries in the field of animal behavior and physiology have provided a rationale for the conviction that unidirectional cause–effect thinking between physiology and behavior is far too limiting. This realization has a parallel in the age-old controversy of nature-nurture. The dualism of nature and nurture may be one of convenience rather than reality. Nature and nurture, like physiology and behavior, or hormones and behavior, are most easily studied as components of a larger system by scientists who have tools to assess one aspect of the dualism better than the other.

  Fig. 13.1 Models used to conceptualize hormones and behavior: hormone to behavior (a), behavior to hormone (b), reciprocal hormones-behavior relations (c), and mediators of hormone and behavior relations (d).

  Contrary to these past approaches, the progression of biological and behavioral research as separate entities now is evolving into a biology–behavior synthesis as reflected in recent theoretical perspectives (Gunnar, 1987 ; Susman, 1993 ) and the content of this volume. In the case of aggression, the perspective proposed here is that aggressive tendencies constitute multicausal phenomena. To understand physiological processes and aggression, these processes should not be viewed as separate causal entities. Physiological processes can be viewed as causes, consequences, or mediators of the psychological constructs of development. Magnusson and Cairns (1992) propose that this multidirectional perspective replaces a “paste on” approach to biological variables that has been prominent in the past.

  Neuroendocrine processes as consequences or mediators of development have not been represented historically in behavioral endocrinology. The traditional experimental approach to understanding the effects of hormones on behavior is to remove the source of the hormone (ablation), to administer exogenous hormones (replacement), and to measure the effects of the exogenous hormone on behavior. This unidirectional model appears in Fig. 13.1a . The following animal-model example illustrates the effect of hormones on behavior while highlighting the importance of the timing of hormone exposure and behavior. Primus and Kellog (1990)

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  Biological Psychiatry

  • Edward Bittar(Author)
  • 1999(Publication Date)
  • Elsevier Science

    (Publisher)

  Chapter 5 The Biology of Aggression PAUL F. BRAIN Introduction Aggression and Genes Aggression and Diet Aggression and Neural Systems Aggression and Hormones Aggression and Drugs Conclusions 103 104 106 107 108 110 111 INTRODUCTION The main problem with specifying the biology of aggression is knowing which phenomena the biological variables should be related to. Aggression is clearly a heterogeneous concept (Brain, 1984) in which biological variables, environmental factors, and social learning all play complex, intertwined roles. Violence is acom-Biological Psychiatry, pages 103-113. Copyright 9 2000by JAI Press Inc. All rightsof reproduction in any form reserved. ISBN: 1-55938-819-6 103 104 PAUL F. BRAIN plex phenomenon and one must specify the importance (and limitations) of genes, diet, neural systems, hormones, and drugs in its expression. Furthermore, as well as forming the basis of some clinical treatments, a knowledge of biological corre-lates may have some predictive value in assessing the risk of aggression in popu-lations of humans. It must also be maintained that individuals with greatly disor-dered biologies (e.g., brain tumors or endocrine disorders) cannot be regarded as wholly responsible for their actions, but the legitimate use of such claims in legal circles is often contentious. It should be self-evident that there are considerable dangers in seeking to equate all examples of human aggression to medical disor-ders. If a disordered biology has a role, it is only likely to be of relevance to some forms of interpersonal behavior, not group activities such as riots and war, which clearly have a largely sociocultural basis. It should be admitted at the outset that even focusing on particular expressions of aggression, such as assault, homicide, or rape, does not lead to simple associations with biological factors.

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  Biological Foundations of Emotion

  • Robert Plutchik, Henry Kellerman, Robert Plutchik, Henry Kellerman(Authors)
  • 2013(Publication Date)
  • Academic Press

    (Publisher)

  Part III THE BIOLOGY OF AGGRESSION This page intentionally left blank Chapter 9 BIOLOGICAL BASES OF AGGRESSIVE BEHAVIOR KENNETH E. MOYER ABSTRACT A model is proposed to account for aggressive behavior. The basic premise of this model states that there are, in the brains of animals and humans, specific neural systems for the various types of aggression. When these neural systems fire in the presence of a relevant target, aggressive behavior ensues. It has now been shown repeatedly that a cat with implanted electrodes will show a specific aggressive behavior, depending on what portion of the brain is stimulated. Humans who have electrodes implanted in their brains, for therapeutic reasons, have shown incipient rage when properly stimulated. The reaction occurs in spite of the fact that they are unaware of the stimulation. A variety of dysfunctions in the brain of humans increase irritability level and the expression of hostility. Some brain tumors, particularly in the temporal lobe, may be associated with increasing levels of aggression, from verbal aggression to homicidal rage. If the tumor is removed successfully, the patient regains his normal personality. Other brain dysfunctions producing a similar result include diffuse head injuries, caused by falls and automobile accidents, brain damage caused by rabies, encephalitis lethargica, and some kinds of epilepsy. Inhibition of the neural systems for aggression can be accomplished in several ways. There are neural systems that tend to block activity in their aggressive counterparts. Thus, it is possible to stimulate an enraged and threatening patient and make of him a rational, pleasant person. Although it may be a dubious therapy, aggressive behavior can be reduced by making lesions in parts of the aggressive neural system. Changes 219 EMOTION: Theory, Research, and Experience Volume 3 Copyright © 1986 by Academic Press, Inc. All rights of reproduction in any form reserved.

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  Neurobiology of Aggression and Rage

  • Allan Siegel(Author)
  • 2004(Publication Date)
  • CRC Press

    (Publisher)

  29 3 The Neuroanatomy of Aggression and Rage A basic question is whether it is necessary or even useful to attempt to understand the neurobiology of aggression and rage by first determining their neuroanatomical substrates. This is a philosophical question because a person who accepts this approach basically identifies with a strategy that is deemed necessary for under-standing the nature of the behavioral processes linked to aggression and rage. This approach is adopted in this book and, hopefully, its advantages will be self-evident from a perusal of this chapter. In Chapter 2, I reviewed from a historical perspective the knowledge base of the brainstem and forebrain structures that play important if not critical roles in the organization and expression of rage behavior. In this chapter, the primary focus is on the circuits in the brain that mediate the expression of defensive rage and predatory attack behavior. The studies described in Chapter 2 provided the back-ground for the present studies. Accordingly, the conclusions of these studies again are summarized here as a means of providing the rational basis for the anatomical studies described below. Results of ablation, lesion, and stimulation studies all point to the likelihood that the medial hypothalamus and periaqueductal gray (PAG) contain the key neu-ronal pools that are necessary for the expression of defensive rage behavior, and that the lateral hypothalamus is the central structure for the expression of predatory attack behavior. NEUROANATOMICAL METHODS The efferent pathways from the hypothalamus and regions of the PAG that mediate aggressive behavior were examined for the first time by Chi and Flynn (1971a, 1971b) and at a later times by Fuchs et al.

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  Origins of Aggression

  • Willard W. Hartup, Jan de Wit, Willard W. Hartup, Jan de Wit(Authors)
  • 2019(Publication Date)
  • De Gruyter Mouton

    (Publisher)

  Aggressive behavior and its brain mechanisms (as exemplified by an experimental analysis of the rat's mouse-killing behavior)* P I E R R E K A R L I Université Louis Pasteur, Strasbourg As this paper will focus on a certain kind of aggressive behavior, two general remarks should be made by way of introduction: 1. Internal milieu factors (glycemia, osmolarity, sexual hormone levels) play an essential role in the elicitation of behaviors (eating, drinking, sexual and maternal behaviors) which form an integral part of some basic biological regulation. The detection of humoral fluctua-tions plays a preponderant part in the processes giving rise to the relevant 'specific arousals' or 'drive states' (hunger, thirst, sexual and maternal 'drives'). In many instances of aggressive behavior, there does not seem to exist any such humoral factor which could be held responsible for the production of a specific drive state ('aggressiveness') arising internally. Social behavior is often shaped essentially by the life-history, by both the general and the more specific history of re-inforcement. There are intimate relations between emotional and social responsiveness, in their progressive shaping during ontogenesis as well as in their behavioral expression in the adult organism. This notion should not lead one to minimize the part taken by humoral factors in the elaboration of any kind of behavioral response. Internal milieu fluctuations as well as changes in the turnover rates of brain neurohumors do affect one or the other of the various aspects of an * This research has been supported since 1966 by grants from the Direction des Recherches et Moyens d'Essais du Ministère des Armées (DRME) and from the Institut National de la Santé et de la Recherche Médicale (INSERM). The major part of the experimental work referred to in this paper was done in collaboration with M. Vergnes, F. Eclancher, J. P. Chaurand and P. Schmitt.

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  Handbook of Medical Psychiatry

  • Jair C. Soares, Samuel Gershon, Jair C. Soares, Samuel Gershon(Authors)
  • 2003(Publication Date)
  • CRC Press

    (Publisher)

  E. Neuroanatomical Correlates of Aggression: Summary Neuroanatomical findings suggest that areas of the brain richly innervated with 5HT neurons (e.g., the orbitofrontal cortex, limbic cortex, temporal lobe) appear to regulate aggression. This is consistent with the neurobiological research showing a primary role for 5HT in the regulation of aggression. If abnormal-ities in 5HT functioning in temporal, limbic, and/or prefrontal cortex contribute to pathological aggres-sion, the question remains to what extent are these abnormalities are heritable, developmental, or acquired. IV. GENETIC STUDIES OF AGGRESSION As stated earlier, aggression is a complex, multideter-mined behavior whose expression is likely affected by numerous environmental and biological factors, as well as the exponential interactions between the two. Behavioral genetic studies are useful in that they provide a rough estimate of the extent to which inher-ited biological factors may influence expression of a behavior. A. Twin Studies Twins studies examine the relative concordance rates of monozygotic (MZ) and dizygotic (DZ) siblings in the expression of a behavior to estimate the heritability for that behavior. Twin studies have generally yielded varible results ranging from findings that genetic influ-ences account for close to 50% of the variance in aggression [128,129], to failing to find a significant increase in the concordance of MZ twins as compared to DZ twins for aggressive behavior [130,131]. One study that examined aggression amongst a population of male twins found that the heritability of aggression is a function of the type and severity of the aggressive acts committed [132]. Life history of verbal aggression, often considered a milder form of aggression was shown to have a heritability esti-mate of 28%. In contrast, life history of direct phy-sical aggression (e.g., fist fights) had a heritability estimate of 47%.

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  Social Psychology

  • Saba Safdar, Catherine A. Sanderson(Authors)
  • 2021(Publication Date)
  • Wiley

    (Publisher)

  Although this definition doesn’t specify the means by which harm is done, it does highlight the actual aggressive act, the perpetrator’s intention to harm, and the victim’s desire to avoid the harm. Based on this definition, aggressive acts don’t include accidents (e.g., unintentionally hitting some- one with an errant golf ball), or assertive acts (e.g., asking for a refund for your new but defective television), but they would include acts where there was an intention to harm, even when there was no actual harm. From a behavioural perspective, aggressive behaviour results in physical and personal inju- ries (Bandura, 1973) and from a cognitive perspective, aggression is behaviour that is intended to harm another individual (Scherer, Abeles, & Fischer 1975). The conceptual difference between these two perspectives is that Bandura focuses on the outcomes of behaviour, while Scherer and colleagues take a more cognitive-motivational approach, focusing on the intention of the perpetrator. In the following section, we examine aggression from biological and social perspectives. PREVIEW emotional or hostile aggression – aggression in which one inflicts harm for its own sake on another instrumental aggression – aggres- sion in which one inflicts harm in order to obtain something of value aggression – physical or verbal behaviour that is intended to harm another individual who is motivated to avoid such treatment 333 How Do Biological Factors Influence Aggression? HOW DO BIOLOGICAL FACTORS INFLUENCE AGGRESSION? One of the most basic and fundamental factors that influences aggression is biological make-up. Serotonin is a neurotransmitter in the brain that helps regulate mood. Serotonin levels have been theorized to play a role in aggression for decades but have only been confirmed recently because of the advancement of brain imaging techniques.

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  Borderline Personality Disorder

  • Mary C. Zanarini(Author)
  • 2005(Publication Date)
  • CRC Press

    (Publisher)

  One of the most consis-tent findings in these studies is the association between low serotonin in the brain and impulsive aggression. Emerging data also indicate a role for other central systems and genomic effects. This review will summarize the 83 neuropsychopharmacological data relevant to these systems and then will briefly review the pharmacological treatment of aggression. Because the vast majority of work in the field involves aggression in general, and because there is no data to suggest that the biology of aggres-sion in patients with BPD is different from that in personality disorder in general, this review will not focus on the neurobiology of BPD specifically. 2. NEUROPSYCHOPHARMACOLOGY OF AGGRESSION 2.1. Serotonin Using cerebrospinal fluid 5-hydroxyindoleacetic acid (CSF 5-HIAA) con-centration as a biomarker of overall central 5-HT system function, Brown et al. (2) first reported an inverse correlation between CSF 5-HIAA concen-tration and a life history of aggression in 26 personality disordered navy recruits with severe behavioral problems. This finding was replicated by the same authors in a similar group of patients (3). Both studies displayed a trivariate relationship between reduced CSF 5-HIAA, aggression and sui-cidal behavior such that reduced CSF 5-HIAA concentration was seen as a function of both aggression and suicidal behavior, each of which was directly correlated. Later reports (4–6) suggested that ‘‘impulsiveness’’ was a key behavioral correlate of reduced 5-HT activity since reduced CSF 5-HIAA concentrations are found in impulsive violent offenders, in impul-sive arsonists, but not in offenders with histories of premeditated aggression (7). Similar results with an inverse relation between CSF 5-HIAA and aggression and/or impulsivity have also been reported in alcoholic males (8), behaviorally disruptive children and adolescents (9), and in rhesus (10) and pigtailed macaques (11).

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