Disparate changes in plasma and brainstem cytokine levels in adult and ageing rats associated with age-related changes in facial motor neuron number, snout muscle morphology, and exploratory behavior

Viythia Katharesan, Martin David Lewis, Robert Vink, Ian Paul Johnson*

*Corresponding author for this work

Research output: Contribution to journalArticle

3 Citations (Scopus)
4 Downloads (Pure)

Abstract

An overall increase in inflammatory cytokines with age in both the blood and the central nervous system (CNS) has been proposed to explain many aspects of ageing, including decreased motor function and neurodegeneration. This study tests the hypothesis that age-related increases in inflammatory cytokines in the blood and CNS lead to facial motor neuron degeneration. Groups of 3-5 female Sprague-Dawley rats aged 3, 12-18, and 24 months were used. Twelve cytokines interleukin (IL)-1α, IL-β, IL-2, IL-4, IL-5, IL-6, IL-10, IL-12p70, IL-13, tumor necrosis factor-a (TNFa), interferon-γ, and granulocyte macrophage-colony stimulating factor were measured in blood plasma and compared with those in the brainstem after first flushing blood from its vessels. The open-field test was used to measure exploratory behavior, and the morphology of the peripheral target muscle of facial motor neurons quantified. Total numbers of facial motor neurons were determined stereologically in separate groups of 3- and 24-month-old rats. Ageing rats showed a significant 30-42% decrease in blood plasma (peripheral) concentrations of IL-12p70 and TNFa and a significant 43-49% increase in brainstem (central) concentrations of IL-1α, IL-2, IL-4, IL-10, and TNFα. They also showed significant reductions in motor neuron number in the right but not left facial nucleus, reduced exploratory behavior, and increase in peripheral target muscle size. Marginal age-related facial motoneuronal loss occurs in the ageing rat and is characterized by complex changes in the inflammatory signature, rather than a general increase in inflammatory cytokines.

Original languageEnglish
Article number191
Pages (from-to)1-9
Number of pages9
JournalFrontiers in Neurology
Volume7
Issue numberNOV
DOIs
Publication statusPublished - 7 Nov 2016
Externally publishedYes

Bibliographical note

Copyright the Author(s) 2016. Version archived for private and non-commercial use with the permission of the author/s and according to publisher conditions. For further rights please contact the publisher.

Keywords

  • Ageing
  • Cytokines
  • Inflammaging
  • Motor neurons
  • Neurodegeneration
  • Rat

Fingerprint Dive into the research topics of 'Disparate changes in plasma and brainstem cytokine levels in adult and ageing rats associated with age-related changes in facial motor neuron number, snout muscle morphology, and exploratory behavior'. Together they form a unique fingerprint.

Cite this