• Welcome to Phoenix Rising!

    Created in 2008, Phoenix Rising is the largest and oldest forum dedicated to furthering the understanding of and finding treatments for complex chronic illnesses such as chronic fatigue syndrome (ME/CFS), fibromyalgia (FM), long COVID, postural orthostatic tachycardia syndrome (POTS), mast cell activation syndrome (MCAS), and allied diseases.

    To become a member, simply click the Register button at the top right.

Immune reaction to viruses may cause learning and memory problems

natasa778

Senior Member
Messages
1,774
Although immune system activation by viruses has long been linked to cognitive problems, the underlying mechanisms have been poorly understood. In the new report, researchers found that virus-associated immune activation causes a loss of connections between nerve cells within brain circuits in the cortex, the brain region responsible for learning. Such mice then do worse on established tests of learning ability.

The observed changes in nerve connections were triggered, not in the brain, but out in the body (the periphery) where viral infection first makes contact with CX3CR1highLY6Clow monocytes in the bloodstream, say the authors.

"This study in animals resonates with what we see in the clinic, where patients with acute or chronic infectious diseases often have weaker performance on motor skills and experience memory decline," says Guang Yang, PhD, assistant professor in the Department of Anesthesiology, Perioperative Care, and Pain Medicine at NYU Langone. "Our results suggest that existing anti-inflammatory treatments that target TNFα may protect against brain dysfunction during peripheral infection." ...

In the current study, experiments found that, once exposed to a mimic (mimetic) of viral infection called poly(I:C), mice eliminated more than twice the percentage of dendritic spines as did mice whose immune systems were not activated, suggesting the disruption of synaptic networks.

Furthermore, in mice being trained to run on a rotating rod, which requires muscle coordination (motor) learning, those exposed to poly(I:C) formed significantly fewer dendritic spines.

Researchers also measured the levels of pro-inflammatory signaling proteins (cytokines) in mice at several time points after the injection of poly(I:C), and found a larger, longer-lasting increase in levels of TNFα than in other cytokines. Given their findings, the team guessed that the impact of systemic immune response on brain cell connections was executed through TNFα signaling. Indeed, mice engineered to lack TNFα signals in white blood cells saw neither a drop in dendritic spine formation nor in motor learning ability when exposed to the viral mimetic.


Read more at: https://medicalxpress.com/news/2017-05-immune-reactions-viruses-problems.html#jCp
 

Marco

Grrrrrrr!
Messages
2,386
Location
Near Cognac, France
This reminded me of a study a few years ago reporting an association between various alleles of the TNF-a (amongst others) receptor gene TRAF1-C5 and measures of quality of life (not specific to the disease e.g. vitality; mental health; mental and social function) in patients with primary biliary cirrhosis :

TRAF1-C5 Affects Quality of Life in Patients with Primary Biliary Cirrhosis

Abstract

Background. Previous studies reported associations between specific alleles of non-HLA immunoregulatory genes and higher fatigue scores in patients with primary biliary cirrhosis (PBC). Aim. To study the relationship between variables of health-related quality of life (HRQoL) and single nucleotide polymorphisms of TRAF1-C5, a member of the tumor necrosis factor receptor family. Patients and Methods. TRAF1-C5 gene polymorphisms, rs2900180 and rs3761847, were analysed in 120 Caucasian PBCs. The HRQoL was assessed with SF-36, PBC-40, and PBC-27 questionnaires. Results. We found a negative association between TT genotype of rs2900180 and SF-36’s domains vitality (), mental health (), and mental component summary score (). GG homozygotes of rs3761847 had lower vitality (), mental health (), mental component summary score () and impairment of social functioning (). Allelic analysis has shown that T allele of rs2900180 and G allele of rs3761847 related to SF-36’s vitality ( and ), social functioning ( and ), mental health ( and ), and mental component summary score ( and ), respectively. Genotyping and allelic analysis did not reveal correlation with PBC-40 and PBC-27 domains. Conclusion. The association between rs2900180 and rs3761847 polymorphisms and HRQoL variables indicates that TRAF1 is involved in the induction of impaired QoL in PBC.

https://www.hindawi.com/journals/jir/2013/510547/