Dietary l-tryptophan leaves a lasting impression on the brain and the stress response

Erik Höglund, Øyvind Øverli, Madelene Åberg Andersson, Patricia Isabel da Mota E. Silva, Danielle Caroline Laursen, Maria M Moltesen, Åshild Krogdahl, Joachim Schjolden, Svante Winberg, Marco A. Vindas, Ian Mayer, Marie Hillestad

Research output: Contribution to journalJournal articleResearchpeer-review

568 Downloads (Pure)

Abstract

Comparative models suggest that effects of dietary tryptophan (Trp) on brain serotonin (5-hydroxytryptamine; 5-HT) neurochemistry and stress responsiveness are present throughout the vertebrate lineage. Moreover, hypothalamic 5-HT seems to play a central role in control of the neuroendocrine stress axis in all vertebrates. Still, recent fish studies suggest long-term effects of dietary Trp on stress responsiveness, which are independent of hypothalamic 5-HT. Here, we investigated if dietary Trp treatment may result in long-lasting effects on stress responsiveness, including changes in plasma cortisol levels and 5-HT neurochemistry in the telencephalon and hypothalamus of Atlantic salmon. Fish were fed diets containing one, two or three times the Trp content in normal feed for 1 week. Subsequently, fish were reintroduced to control feed and were exposed to acute crowding stress for 1 h, 8 and 21 d post Trp treatment. Generally, acute crowding resulted in lower plasma cortisol levels in fish treated with 3×Trp compared with 1×Trp- and 2×Trp-treated fish. The same general pattern was reflected in telencephalic 5-HTergic turnover, for which 3×Trp-treated fish showed decreased values compared with 2×Trp-treated fish. These long-term effects on post-stress plasma cortisol levels and concomitant 5-HT turnover in the telencephalon lends further support to the fact that the extrahypothalamic control of the neuroendocrine stress response is conserved within the vertebrate lineage. Moreover, they indicate that trophic/structural effects in the brain underlie the effects of dietary Trp treatment on stress reactivity.
Original languageEnglish
JournalBritish Journal of Nutrition
Volume117
Issue number10
Pages (from-to)1351-1357
ISSN0007-1145
DOIs
Publication statusPublished - 2017

Keywords

  • l-Tryptophan
  • 5-HIAA 5-hydroxyindoleacetic acid
  • 5-HT 5-hydroxytryptamine (serotonin)
  • HPI hypothalamic–pituitary–interrenal
  • SSRI supplementation and serotonin reuptake inhibitors
  • Trp tryptophan
  • Long-term effects
  • Monoamines

Fingerprint

Dive into the research topics of 'Dietary l-tryptophan leaves a lasting impression on the brain and the stress response'. Together they form a unique fingerprint.

Cite this