Research Brief

Study uncovers the basis of COVID-19-related brain fog

Microscopic view of the virus that causes COVID-19." Image size: 900x600 for web; 75% scale in email
New U of M research examines the specific ways SARS-CoV-2 impacts the brain. Credit: University of Minnesota

Neurological symptoms have been widely observed in COVID-19 patients, with many survivors exhibiting persistent neurological and cognitive impairment. New research from the University of Minnesota found that COVID-19 triggers inflammation in the brain, which is linked to many COVID-related symptoms such as fatigue and “brain fog.” 

Published in 
Frontiers in Microbiology, the researchers examined the specific ways the virus impacts the brain, developing a preclinical model to accurately mimic the effects of COVID-19 on humans to explore the impact of age and sex on the brain-related impacts of the disease. 

The study was led by Maxim Cheeran in the College of Veterinary Medicine, Ling Li in the College of Pharmacy and Walter Low in the Medical School. The findings include:

  • SARS-CoV-2 infection triggered a neuroinflammatory response, despite the lack of detectable virus in the brain. 
  • Older age males showed a higher viral load and more pronounced symptoms. 
  • Older age also led to increased neurological inflammation. 

The researchers also found several biological pathways that the virus impacts in the brain, including overactive or misdirected immune response, disruption to the protective blood-brain barrier, damage to cells lining blood vessels, and impacts to how nerve cells are formed and function. These impacts can impair brain function and may even lead to permanent damage.

“There are still things we don’t know about how coronavirus infection affects the brain, and our research is beginning to unravel the mystery,” said Cheeran. “We now know that viral infection in the lungs can cause inflammatory changes in the brain, affected by the age and sex of the patient. With this model, we can further examine the connections between the infected lung and the brain, and start development on targeted treatments to mitigate the impact of COVID-19 on the brain.”

In addition to new targeted therapies, these findings allow for more accurate vaccine development and continued research. The research team has a study underway that could shed light on the persistence of these symptoms in individuals experiencing long COVID, including the long-term impacts on neurocognitive behavior and memory loss.

This work was supported in part by grants from the National Institutes of Health/National Institute on Aging and the SURRGE award program of the University of Minnesota’s College of Pharmacy.

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About the College of Veterinary Medicine
The University of Minnesota College of Veterinary Medicine affects the lives of animals and people every day through educational, research, service, and outreach programs. Established in 1947, the University of Minnesota College of Veterinary Medicine is Minnesota’s only veterinary college. Fully accredited, the college has graduated over 4,000 veterinarians and hundreds of scientists. The college is also home to the Veterinary Medical Center, the Veterinary Diagnostic Laboratory, the Leatherdale Equine Center and The Raptor Center. Learn more at vetmed.umn.edu.

About the College of Pharmacy
Founded in 1892, the University of Minnesota College of Pharmacy is the only pharmacy school in Minnesota, with campuses in the Twin Cities and in Duluth. The College of Pharmacy improves health through innovative education, pioneering research and interdisciplinary practice development that attends to the diverse needs of the people of Minnesota and the world. Learn more at pharmacy.umn.edu.

About the Medical School
The University of Minnesota Medical School is at the forefront of learning and discovery, transforming medical care and educating the next generation of physicians. Our graduates and faculty produce high-impact biomedical research and advance the practice of medicine. We acknowledge that the U of M Medical School is located on traditional, ancestral and contemporary lands of the Dakota and the Ojibwe, and scores of other Indigenous people, and we affirm our commitment to tribal communities and their sovereignty as we seek to improve and strengthen our relations with tribal nations. Learn more at med.umn.edu.

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Rachel Cain

University Public Relations
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