Reciprocal interaction between the suprachiasmatic nucleus and the immune system tunes down the inflammatory response to lipopolysaccharide

J Neuroimmunol. 2014 Aug 15;273(1-2):22-30. doi: 10.1016/j.jneuroim.2014.05.012. Epub 2014 May 29.


Several studies have shown circadian variations in the response of the immune system suggesting a role of the suprachiasmatic nucleus (SCN). Here we show that lipopolysaccharide (LPS) administration in the beginning of the active period induced more severe responses in temperature and cytokines than LPS given in the rest period. Moreover night administered LPS increased SCN basal neuronal activity indicating a direct influence of inflammation on the SCN. Bilateral lesions of the SCN resulted in an increased inflammatory response to LPS demonstrating that an interaction between the SCN and the immune system modulates the intensity of the inflammatory response.

Keywords: Circadian rhythms; Cytokines; LPS; Temperature response; Wistar rats.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adjuvants, Immunologic / pharmacology
  • Animals
  • Body Temperature / drug effects
  • Cell Count
  • Circadian Rhythm / drug effects
  • Cytokines / metabolism
  • Dose-Response Relationship, Drug
  • Immune System / drug effects*
  • Inflammation / chemically induced
  • Inflammation / metabolism*
  • Inflammation / pathology
  • Lipopolysaccharides / pharmacology*
  • Male
  • Neurons / drug effects
  • Proto-Oncogene Proteins c-fos / metabolism
  • Rats
  • Rats, Wistar
  • Suprachiasmatic Nucleus / cytology
  • Suprachiasmatic Nucleus / drug effects*
  • Suprachiasmatic Nucleus / metabolism
  • Time Factors


  • Adjuvants, Immunologic
  • Cytokines
  • Lipopolysaccharides
  • Proto-Oncogene Proteins c-fos