Researchers from King’s College London have shown that when brain cells are directly exposed to blood taken from COVID-19 patients with delirium, there is an increase in cell death and a decrease in the generation of new brain cells. Delirium represents a state of confusion indicating that, in these patients, the COVID-19 infection had impacted the brain.
Published in Molecular Psychiatry, the study’s findings indicate a key role for the inflammatory proteins (cytokines) produced by the immune system during infection, and could help inform potential treatments to reduce symptoms of confusion, disorientation and memory deficits in COVID-19 patients.
Dr. Alessandra Borsini, NIHR Maudsley BRC Senior Research Fellow, Institute of Psychiatry, Psychology & Neuroscience, first author, said, “More and more, research is indicating that there is a neurological element to severe COVID-19 infection, but we have little understanding about what happens in the brain to produce these symptoms. Our research is the first to use blood samples from COVID-19 patients experiencing delirium to investigate how the infection impacts a process called ‘neurogenesis’ (the generation of new brain cells), which is essential to maintain intact brain functions, including memory and thought processes.
“We have found that there is a profound reduction in the generation of new brain cells and an increase in cell death, and these are likely mechanisms behind delirium, and possibly other neurological symptoms, in COVID-19 patients.”
Previous research indicates that 20 to 30% of COVID-19 patients will develop neurological symptoms such as delirium, with rates of 60 to 70% in cases of severe illness. Delirium is a state of mental confusion that can happen if you become medically unwell and is associated with adverse outcomes, including prolonged hospitalization and death.
The development of neurological symptoms in COVID-19 patients is likely to involve an overactive immune response, called the cytokine storm, with an excessive production of these multiple inflammatory proteins. Once produced by the immune cells in the body in response to the infection, these cytokines can then move from the blood to the brain and directly affect brain mechanisms. However, which cytokines are directly relevant to the development of neurological symptoms is currently unknown.
The study collected serum samples from 36 patients admitted to Guy’s and St Thomas’ NHS Foundation Trust, in London, during the first wave of the COVID-19 pandemic in the UK (March-June 2020). Half of these patients were experiencing delirium symptoms whilst the other half did not present with these symptoms at time of hospital admission.
Researchers used a validated in vitro human cell model that consists of cells from the hippocampus, a part of the brain fundamental in many cognitive, memory and learning skills. Researchers treated cells from the hippocampus directly with the serum samples and observed the impacts on cell generation and death, as well as on the levels of different cytokines.
Results showed that treatment with serum taken from COVID-19 patients with delirium increased cell death and decreased generation of new brain cells. Investigation of the serum showed that those patients with delirium had higher levels of the cytokine IL6, while there was no difference between patients on other cytokines. Treating the brain cells with the serum did produce higher levels of two other cytokines—IL12 and IL13 –suggesting there is a process or cascade where IL12 and I1L3 are generated by brain cells in response to inflammation in the body created by IL6, and together they produce the delirium.
Author Professor Carmine Pariante, Professor of Biological Psychiatry at the Institute of Psychiatry Psychology & Neuroscience (IoPPN), and Consultant Perinatal Psychiatrist at South London and Maudsley NHS Foundation Trust, said, “The role of inflammation and our immune response in COVID-19 infection is well-known, but research like ours is now revealing how it affects our brain, our thinking and our mental health.
“Through a series of tests, we have shown that it is likely that the initial production of cytokine proteins as part of the inflammatory response in COVID-19 infection triggers a cascade of other cytokines which reduce generation of new brain cells and increase cell death, leading to brain symptoms such as delirium. These neurological symptoms are very concerning for patients and their families, and the hope is that our research can help identify which treatments would be most appropriate to lessen or prevent these symptoms.”

News
New Once-a-Week Shot Promises Life-Changing Relief for Parkinson’s Patients
A once-a-week shot from Australian scientists could spare people with Parkinson’s the grind of taking pills several times a day. The tiny, biodegradable gel sits under the skin and releases steady doses of two [...]
Weekly injectable drug offers hope for Parkinson’s patients
A new weekly injectable drug could transform the lives of more than eight million people living with Parkinson's disease, potentially replacing the need for multiple daily tablets. Scientists from the University of South Australia [...]
Most Plastic in the Ocean Is Invisible—And Deadly
Nanoplastics—particles smaller than a human hair—can pass through cell walls and enter the food web. New research suggest 27 million metric tons of nanoplastics are spread across just the top layer of the North [...]
Repurposed drugs could calm the immune system’s response to nanomedicine
An international study led by researchers at the University of Colorado Anschutz Medical Campus has identified a promising strategy to enhance the safety of nanomedicines, advanced therapies often used in cancer and vaccine treatments, [...]
Nano-Enhanced Hydrogel Strategies for Cartilage Repair
A recent article in Engineering describes the development of a protein-based nanocomposite hydrogel designed to deliver two therapeutic agents—dexamethasone (Dex) and kartogenin (KGN)—to support cartilage repair. The hydrogel is engineered to modulate immune responses and promote [...]
New Cancer Drug Blocks Tumors Without Debilitating Side Effects
A new drug targets RAS-PI3Kα pathways without harmful side effects. It was developed using high-performance computing and AI. A new cancer drug candidate, developed through a collaboration between Lawrence Livermore National Laboratory (LLNL), BridgeBio Oncology [...]
Scientists Are Pretty Close to Replicating the First Thing That Ever Lived
For 400 million years, a leading hypothesis claims, Earth was an “RNA World,” meaning that life must’ve first replicated from RNA before the arrival of proteins and DNA. Unfortunately, scientists have failed to find [...]
Why ‘Peniaphobia’ Is Exploding Among Young People (And Why We Should Be Concerned)
An insidious illness is taking hold among a growing proportion of young people. Little known to the general public, peniaphobia—the fear of becoming poor—is gaining ground among teens and young adults. Discover the causes [...]
Team finds flawed data in recent study relevant to coronavirus antiviral development
The COVID pandemic illustrated how urgently we need antiviral medications capable of treating coronavirus infections. To aid this effort, researchers quickly homed in on part of SARS-CoV-2's molecular structure known as the NiRAN domain—an [...]
Drug-Coated Neural Implants Reduce Immune Rejection
Summary: A new study shows that coating neural prosthetic implants with the anti-inflammatory drug dexamethasone helps reduce the body’s immune response and scar tissue formation. This strategy enhances the long-term performance and stability of electrodes [...]
Scientists discover cancer-fighting bacteria that ‘soak up’ forever chemicals in the body
A family of healthy bacteria may help 'soak up' toxic forever chemicals in the body, warding off their cancerous effects. Forever chemicals, also known as PFAS (per- and polyfluoroalkyl substances), are toxic chemicals that [...]
Johns Hopkins Researchers Uncover a New Way To Kill Cancer Cells
A new study reveals that blocking ribosomal RNA production rewires cancer cell behavior and could help treat genetically unstable tumors. Researchers at the Johns Hopkins Kimmel Cancer Center and the Department of Radiation Oncology and Molecular [...]
AI matches doctors in mapping lung tumors for radiation therapy
In radiation therapy, precision can save lives. Oncologists must carefully map the size and location of a tumor before delivering high-dose radiation to destroy cancer cells while sparing healthy tissue. But this process, called [...]
Scientists Finally “See” Key Protein That Controls Inflammation
Researchers used advanced microscopy to uncover important protein structures. For the first time, two important protein structures in the human body are being visualized, thanks in part to cutting-edge technology at the University of [...]
AI tool detects 9 types of dementia from a single brain scan
Mayo Clinic researchers have developed a new artificial intelligence (AI) tool that helps clinicians identify brain activity patterns linked to nine types of dementia, including Alzheimer's disease, using a single, widely available scan—a transformative [...]
Is plastic packaging putting more than just food on your plate?
New research reveals that common food packaging and utensils can shed microscopic plastics into our food, prompting urgent calls for stricter testing and updated regulations to protect public health. Beyond microplastics: The analysis intentionally [...]