Mechanism of acute tryptophan depletion: is it only serotonin?

E.L. van Donkelaar*, A. Blokland, L. Ferrington, P.A. Kelly, H.W.M. Steinbusch, J. Prickaerts

*Corresponding author for this work

Research output: Contribution to journal(Systematic) Review article peer-review

Abstract

The method of acute tryptophan depletion (ATD), which reduces the availability of the essential amino acid tryptophan (TRP), the dietary serotonin (5-hydroxytryptamine (5-HT)) precursor, has been applied in many experimental studies. ATD application leads to decreased availability of TRP in the brain and its synthesis into 5-HT. It is therefore assumed that a decrease in 5-HT release and subsequent blunted neurotransmission is the underlying mechanism for the behavioural effects of ATD. However, direct evidence that ATD decreases extracellular 5-HT concentrations is lacking. Furthermore, several studies provide support for alternative underlying mechanisms of ATD. This may question the utility of the method as a selective serotonergic challenge tool. As ATD is extensively used for investigating the role of 5-HT in cognitive functions and psychiatric disorders, the potential of alternative mechanisms and possible confounding factors should be taken into account. It is suggested that caution is required when interpreting ATD effects in terms of a selective serotonergic effect. Molecular Psychiatry (2011) 16, 695-713; doi:10.1038/mp.2011.9; published online 22 February 2011

Original languageEnglish
Pages (from-to)695-713
Number of pages19
JournalMolecular Psychiatry
Volume16
Issue number7
DOIs
Publication statusPublished - Jul 2011

Keywords

  • acute stress
  • cerebral blood flow
  • cognitive dysfunction
  • depression
  • serotonin
  • tryptophan
  • LONG-TERM POTENTIATION
  • CENTRAL-NERVOUS-SYSTEM
  • GELATIN-BASED MIXTURE
  • CEREBRAL-BLOOD-FLOW
  • IMPAIRS OBJECT MEMORY
  • NITRIC-OXIDE SYNTHASE
  • DORSAL RAPHE NUCLEUS
  • AMINO-ACID MIXTURES
  • BRAIN TRYPTOPHAN
  • PLASMA TRYPTOPHAN

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