Immunity impacts cognitive deficits across neurological disorders

Area of Science:

• Neuroscience
• Immunology
• Pathology

Background:

• Cognitive deficits are prevalent in neurological disorders (Alzheimer's, MS, FTLD, PD), TBI, MDD, and normal aging.
• Neuroinflammation, involving cytokine and chemokine release by CNS cells, is increasingly linked to these cognitive impairments.
• Specific cytokines like TNFα and IL-6 show strong associations with cognitive decline across diverse conditions.

Purpose of the Study:

• To review the role of cytokines and chemokines in cognitive deficits across various neurological and psychological disorders.
• To explore the commonalities in inflammatory pathways underlying cognitive impairment in conditions such as Alzheimer's disease, multiple sclerosis, and major depressive disorder.
• To propose that immune dysregulation contributes to neuropsychiatric symptoms via aberrant cytokine expression.

Main Methods:

• Literature review of studies examining cytokine and chemokine involvement in neurological and psychological disorders.
• Analysis of overlapping cytokine expression profiles across conditions like Alzheimer's disease, multiple sclerosis, frontotemporal lobe dementia, Parkinson's disease, TBI, and MDD.
• Synthesis of evidence linking neuroinflammation to cognitive function and neuropsychiatric phenotypes.

Main Results:

• Cytokine and chemokine profiles, particularly TNFα and IL-6, are significantly altered in AD, MS, FTLD, PD, TBI, MDD, and normal aging.
• Both CNS-resident and non-resident cells contribute to pathological cytokine expression.
• Cytokines directly affect neuronal function and indirectly influence neural networks via glial crosstalk.

Conclusions:

• Immune system dysregulation and pathological cytokine expression are key contributors to cognitive deficits and neuropsychiatric phenotypes.
• Shared inflammatory mechanisms underlie cognitive impairment in a wide range of neurological and psychological conditions.
• Targeting neuroinflammation presents a potential therapeutic avenue for cognitive dysfunction.