Hypothalamic attack: a wonderful artifact or a useful perspective on escalation and pathology in aggression? A viewpoint.
W.R. Hess' early demonstration of aggressive responses evoked by electrical stimulation in the cat's hypothalamus had a significant impact on the development of psychological and behavioral concepts. Many ideas on behavioral routines, allegedly organized in the brainstem, derive from his observation. Similar responses have since been evoked from the hypothalamus of many different species, suggesting that the mechanism mediating these responses is evolutionarily well preserved. However, these effects have also been portrayed as artificial responses to an artificial stimulus in an artificial environment. True enough; after many years of research, crucial questions on the underlying mechanism remain unanswered. Questions such as: How do they emerge in the first place? What neuronal elements mediate these responses? What is their role in "spontaneous" aggression? In the first part of this chapter we show methodology to study such questions in a consistent way using behavioral, physiological, anatomical, and pharmacological findings on hypothalamic attack in rats. In the second part we suggest that one important function of the underlying mechanism is to match the dynamics of the endocrine stress response with the dynamics of the behavioral and physiological requirements of coping with conflicts. This neuroendocrine-behavioral matching seems crucial right from the first emergence of the aggressive response in inexperienced animals, up to the full-blown violent responding in fully experienced animals. Impeding these essential functions results in inadequate coping with conflicts. The stress response during a first conflict in an inexperienced individual in an unfamiliar environment seems to rapidly initialize a crucial change in a mechanism involved in the appraisal of social signals during conflict. That change has enduring consequences for future conflict strategies. This concept opens another perspective on "escalated" or "pathological" aggression, especially so in individuals with a dysfunctional stress response.
Gorleus Lab, Department of Medical Pharmacology, Leiden Academic Center for Drug Research (LACDR), Leiden University, Einsteinweg 55, 2333 CC, Leiden, Netherlands, Info@Mennokruk.nl.
Menno R
MR
Kruk
D000374:Aggression / Q000502:physiology*; D000818:Animals; D001522:Behavior, Animal / Q000502:physiology*; D001931:Brain Mapping; D006801:Humans; D007031:Hypothalamus / Q000502:physiology*; D009490:Neurosecretory Systems / Q000502:physiology*