Brain cytokines and the 5-HT system during poly I:C-induced fatigue

Toshihiko Katafuchi, Tetsuya Kondo, Sachiko Take, Megumu Yoshimura

Research output: Chapter in Book/Report/Conference proceedingConference contribution

50 Citations (Scopus)


Fatigue is evoked not only by peripheral factors, such asmuscle fatigue, but also by the central nervous system (CNS). For example, it is generally known that the feeling of fatigue is greatly influenced by psychological aspects, such as motivation. However, little is known about the central mechanisms of fatigue. The clinical symptoms of chronic fatigue syndrome (CFS) are shown to include disorders in neuroendocrine, autonomic, and immune systems. On the other hand, it has been demonstrated that cytokines produced in the brain play significant roles in neural-immune interactions through their various central actions, including hypothalamo-pituitary and sympathetic activation, as well as immunosuppression. In this article, using the immunologically induced fatigue model, which was achieved by intraperitoneal (i.p.) injection of synthetic double-stranded RNAs, polyriboinosinic: polyribocytidylic acid (poly I:C) in rats, we show an involvement of brain interferon-α (IFN-α) and serotonin (5-HT) transporter (5-HTT) in the central mechanisms of fatigue. In the poly I:C-induced fatigue rats, expression of IFN-α and 5-HTT increased, while extracellular concentration of 5-HT in the medial prefrontal cortex decreased, probably on account of the enhanced expression of 5-HTT. Since the poly I:C-induced reduction of the running wheel activity was attenuated by a 5-HT1A receptor agonist, but not by 5-HT2, 5-HT 3, or dopamine D3 receptor agonists, it is suggested that the decrease in 5-HT actions on 5-HT1A receptorsmay at least partly contribute to the poly I:C-induced fatigue.

Original languageEnglish
Title of host publicationNeuroendocrine and Immune Crosstalk
PublisherBlackwell Publishing Inc.
Number of pages8
ISBN (Print)1573316237, 9781573316231
Publication statusPublished - Nov 2006

Publication series

NameAnnals of the New York Academy of Sciences
ISSN (Print)0077-8923
ISSN (Electronic)1749-6632

All Science Journal Classification (ASJC) codes

  • General Neuroscience
  • General Biochemistry,Genetics and Molecular Biology
  • History and Philosophy of Science


Dive into the research topics of 'Brain cytokines and the 5-HT system during poly I:C-induced fatigue'. Together they form a unique fingerprint.

Cite this