(Cytokines are chemcals central to the inflammatory process.)


1: J Am Geriatr Soc. 2002 Dec;50(12):2041-56.

Cytokines and cognition--the case for a head-to-toe inflammatory paradigm.

Wilson CJ, Finch CE, Cohen HJ.

St. Vincent Institute on Aging, St. Vincent Hospitals and Health Services,
Indianapolis, Indiana 46260, USA. cjwilson@stvincent.org

The brain is not only immunologically active of its own accord, but also has
complex peripheral immune interactions. Given the central role of cytokines in
neuroimmmunoendocrine processes, it is hypothesized that these molecules
influence cognition via diverse mechanisms. Peripheral cytokines penetrate the
blood-brain barrier directly via active transport mechanisms or indirectly via
vagal nerve stimulation. Peripheral administration of certain cytokines as
biological response modifiers produces adverse cognitive effects in animals and
humans. There is abundant evidence that inflammatory mechanisms within the
central nervous system (CNS) contribute to cognitive impairment via
cytokine-mediated interactions between neurons and glial cells. Cytokines
mediate cellular mechanisms subserving cognition (e.g., cholinergic and
dopaminergic pathways) and can modulate neuronal and glial cell function to
facilitate neuronal regeneration or neurodegeneration. As such, there is a
growing appreciation of the role of cytokine-mediated inflammatory processes in
neurodegenerative diseases such as Alzheimer's disease and vascular dementia.
Consistent with their involvement as mediators of bidirectional communication
between the CNS and the peripheral immune system, cytokines play a key role in
the hypothalamic-pituitary-adrenal axis activation seen in stress and
depression. In addition, complex cognitive systems such as those that underlie
religious beliefs, can modulate the effects of stress on the immune system.
Indirect means by which peripheral or central cytokine dysregulation could
affect cognition include impaired sleep regulation, micronutrient deficiency
induced by appetite suppression, and an array of endocrine interactions. Given
the multiple levels at which cytokines are capable of influencing cognition it
is plausible that peripheral cytokine dysregulation with advancing age interacts
with cognitive aging.

Publication Types:
Review

PMID: 12473019 [PubMed - indexed for MEDLINE]