EN
Physiological studies of neuroendocrine regulation confirm that aggressive behavior patterns are nearly universal in the animal kingdom. Different species of fish (e.g. Zebra Fish and Siamese Fighting Fish) are used as models for studies of animal behavior, including aggression. Despite an increased risk of injury or death, aggression frequently offers considerable benefits. It is mainly related with competition for limited resources, for example, competition for food or a mate, the establishment of territory and dominance hierarchies (a higher social status). Aggression is a kind of aversive drive to limit the freedom of other animals of the same or other species or to injure or kill them. Territorial behavior is a significant problem in farm and companion animals, not only causing economic losses but also threatening animal health and welfare. The following systems are involved in the regulation of aggressive behavior: the hypothalamo-pituitary-adrenocortical (HPA), sympathetico-medullary-adrenal (SAM), hypothalamo-pituitary-interrenal, serotonin, somatostatin, dopamine, histamine and nitric oxide pathways, as well as brain structures responsible for motivation. The aim of this article is to review the present state of knowledge concerning the neuro-endocrine modulation of aggressive behavior in animals.