Life without brain serotonin: reevaluation of serotonin function with mice deficient in brain serotonin synthesis

Behav Brain Res. 2015 Jan 15:277:78-88. doi: 10.1016/j.bbr.2014.06.005. Epub 2014 Jun 11.


Tryptophan hydroxylase (TPH) is a rate limiting enzyme in the synthesis of serotonin (5-HT), a monoamine which works as an autacoid in the periphery and as a neurotransmitter in the central nervous system. In 2003 we have discovered the existence of a second Tph gene, which is expressed exclusively in the brain, and, therefore, is responsible for the 5-HT synthesis in the central nervous system. In the following years several research groups have independently generated Tph2-deficient mice. In this review we will summarize the data gained from the existing mouse models with constitutive or conditional deletion of the Tph2 gene, focusing on biochemical, developmental, and behavioral consequences of Tph2-deficiency.

Keywords: Animal model; Behavior; Serotonin; Serotonin receptors; Serotonin transporter; Tryptophan hydroxylase 2.

Publication types

  • Review

MeSH terms

  • Animals
  • Behavior, Animal / physiology*
  • Brain / metabolism*
  • Disease Models, Animal
  • Humans
  • Receptors, Serotonin / metabolism
  • Serotonin / deficiency*
  • Serotonin / metabolism*
  • Tryptophan Hydroxylase / genetics
  • Tryptophan Hydroxylase / metabolism*


  • Receptors, Serotonin
  • Serotonin
  • Tryptophan Hydroxylase