Aggressiveness is an ancestral behavior common to all animal species. Its neurophysiological mechanismsare similar in all vertebrates. Males are generally more aggressive than females. In this review,aggressive behavior in rodents, monkeys, and man and the role of testosterone and brainserotonin levels have been considered. Interspecifi c aggressiveness in rats has been studied consideringthe mouse-killing behavior; the neonatal androgenization of females increases adult mousekillingas does the administration of testosterone in adults. Intraspecifi c aggressiveness was studiedby putting two or more male rats (or mice) in the same cage; the condition of subjection or dominanceis infl uenced by testosterone.In monkeys, testosterone is related to aggressiveness and dominance and, during the mating season,increases in testosterone levels and aggressive attitude are observed. In men, higher testosteronelevels were obtained in perpetrators of violent crimes, in men from the army with antisocialbehaviors, in subjects with impulsive behaviors, alcoholics and suicidals, in athletes using steroids,and during competitions. Aggressive and dominant behavior are distinguished. Testosterone influences both of these, even if man is usually inclined to affi rm his power without causing physicaldamage. Testosterone receptors are mainly in some hypothalamic neurons, where it is aromatizedinto estrogens, which determine the increase in aggressiveness. A relation between testosteronelevels and diencephalic serotonin has been shown: in fact, the lack of serotonin increases aggressivebehaviors both in animals and man. Testosterone also increases ADH levels in the medial amygdala,lateral hypothalamus, and preoptical medial area, involved in aggressive behaviors.
|Numero di pagine||10|
|Rivista||Medical Science Monitor|
|Stato di pubblicazione||Published - 2005|
All Science Journal Classification (ASJC) codes