From genes to aggressive behavior: the role of serotonergic system

Bioessays. 2006 May;28(5):495-503. doi: 10.1002/bies.20412.


Recent investigations in neurogenomics have opened up new lines of research into a crucial genetic problem-the pathway from genes to behavior. This paper concentrates on the involvement of protein elements in the brain neurotransmitter serotonin (5-HT) system in the genetic control of aggressive behavior. Specifically, it describes: (1) the effect of the knockout of MAO A, the principal enzyme in 5-HT degradation, (2) the association of intermale aggression with the polymorphism in the Tph2 gene encoding the key enzyme in 5-HT synthesis in the brain, tryptophan hydroxylase (TPH), and (3) the effect of selective breeding for nonaggressive behavior on 5-HT metabolism, TPH activity and 5-HT(1A) receptors in the brain. The review provides converging lines of evidence that: (1) brain 5-HT contributes to a critical mechanism underlying genetically defined individual differences in aggressiveness, and (2) genes encoding pivotal enzymes in 5-HT metabolism (TPH and MAO A), 5-HT-transporter, 5-HT(1A) and 5-HT(1B) receptors belong to a group of genes that modulate aggressive behavior.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Aggression / physiology*
  • Animals
  • Behavior, Animal / physiology
  • Brain / physiology
  • Humans
  • Mice
  • Mice, Knockout
  • Models, Neurological
  • Monoamine Oxidase / deficiency
  • Monoamine Oxidase / genetics
  • Monoamine Oxidase / physiology
  • Rats
  • Receptor, Serotonin, 5-HT1A / genetics
  • Receptor, Serotonin, 5-HT1A / physiology
  • Receptor, Serotonin, 5-HT1B / genetics
  • Receptor, Serotonin, 5-HT1B / physiology
  • Serotonin / physiology*
  • Tryptophan Hydroxylase / genetics
  • Tryptophan Hydroxylase / physiology


  • Receptor, Serotonin, 5-HT1B
  • Receptor, Serotonin, 5-HT1A
  • Serotonin
  • Tryptophan Hydroxylase
  • Monoamine Oxidase