PERSONAL USE ONLY Testosterone and aggressiveness Marco Giammanco, Garden Tabacchi, Santo Giammanco, Danila Di Majo, Maurizio La Guardia Institute of Physiology and Human Nutrition, University of Palermo, Palermo, Italy Source of support: Self financing Summary Aggressiveness is an ancestral behavior common to all animal species. Its neurophysiological mech- anisms are similar in all vertebrates. Males are generally more aggressive than females. In this re- view, aggressive behavior in rodents, monkeys, and man and the role of testosterone and brain serotonin levels have been considered. Interspecific aggressiveness in rats has been studied consid- ering the mouse-killing behavior; the neonatal androgenization of females increases adult mouse- killing as does the administration of testosterone in adults. Intraspecific aggressiveness was studied by putting two or more male rats (or mice) in the same cage; the condition of subjection or dom- inance is influenced by testosterone. In monkeys, testosterone is related to aggressiveness and dominance and, during the mating sea- son, increases in testosterone levels and aggressive attitude are observed. In men, higher testoster- one levels were obtained in perpetrators of violent crimes, in men from the army with antisocial behaviors, in subjects with impulsive behaviors, alcoholics and suicidals, in athletes using steroids, and during competitions. Aggressive and dominant behavior are distinguished. Testosterone in- fluences both of these, even if man is usually inclined to affirm his power without causing physical damage. Testosterone receptors are mainly in some hypothalamic neurons, where it is aromatized into estrogens, which determine the increase in aggressiveness. A relation between testosterone levels and diencephalic serotonin has been shown: in fact, the lack of serotonin increases aggres- sive behaviors both in animals and man. Testosterone also increases ADH levels in the medial amy- gdala, lateral hypothalamus, and preoptical medial area, involved in aggressive behaviors. key words: aggressiveness •testosterone • androgen • behavior • dominance • serotonin Full-text PDF: http://www.MedSciMonit.com/pub/vol_11/no_4/4259.pdf Word count: 5510 Tables: — Figures: — References: 137 Author’s address: Marco Giammanco, Ph.D, M.D, Institute of Physiology and Human Nutrition, University of Palermo, via Augusto Elia, e 90127 Palermo, Italy, e-mail: giammanco@unipa.it Received: 2003.10.16 Accepted: 2004.09.29 Published: 2005.04.01 RA136 Review Article WWW. MEDSCIMONIT.COM © Med Sci Monit, 2005; 11(4): RA136-145 PMID: 15795710 Current Contents/Clinical Medicine • SCI Expanded • ISI Alerting System • Index Medicus/MEDLINE • EMBASE/Excerpta Medica • Chemical Abstracts • Index Copernicus Electronic PDF security powered by IndexCopernicus.com opy is for personal use only - distribution prohibited. This copy is for personal use only - distribution prohibited. This copy is for personal use only - distribution prohibited. This copy is for personal use only - distribution prohibited. This copy is for personal use only - distribu