Using post-mortem tissue samples, a team of researchers from Charité – Universitätsmedizin Berlin have studied the mechanisms by which the novel coronavirus can reach the brains of patients with COVID-19, and how the immune system responds to the virus once it does.
The results, which show that SARS-CoV-2 enters the brain via nerve cells in the olfactory mucosa, have been published in Nature Neuroscience.
For the first time, researchers have been able to produce electron microscope images of intact coronavirus particles inside the olfactory mucosa.
It is now recognized that COVID-19 is not a purely respiratory disease. In addition to affecting the lungs, SARS-CoV-2 can impact the cardiovascular system, the gastrointestinal tract and the central nervous system. More than one in three people with COVID-19 report neurological symptoms such as loss of, or change in, their sense of smell or taste, headaches, fatigue, dizziness, and nausea. In some patients, the disease can even result in stroke or other serious conditions.
Until now, researchers had suspected that these manifestations must be caused by the virus entering and infecting specific cells in the brain. But how does SARS-CoV-2 get there?
Under the joint leadership of Dr. Helena Radbruch of Charité’s Department of Neuropathology and the Department’s Director, Prof. Dr. Frank Heppner, a multidisciplinary team of researchers has now traced how the virus enters the central nervous system and subsequently invades the brain.
As part of this research, experts from the fields of neuropathology, pathology, forensic medicine, virology and clinical care studied tissue samples from 33 patients (average age 72) who had died at either Charité or the University Medical Center Göttingen after contracting COVID-19. Using the latest technology, the researchers analyzed samples taken from the deceased patients’ olfactory mucosa and from four different brain regions. Both the tissue samples and distinct cells were tested for SARS-CoV-2 genetic material and a ‘spike protein’ which is found on the surface of the virus.
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Post by Amanda Scott, NA CEO. Follow her on twitter @tantriclens
Thanks to Heinz V. Hoenen. Follow him on twitter: @HeinzVHoenen