German molecular biologists have found that coronavirus penetrates the human brain through the olfactory nasal receptors, the results of an appropriate study published on bioRxiv.
“We discovered the first evidence that SARS-CoV-2 penetrates the human brain through the olfactory epithelium, moving along the olfactory tract to the central regions of the brain. This explains the many characteristic symptoms of COVID-19, including the loss of smell and taste, ”TASS reports scientists.
A group of German scientists led by Frank Heppner and a professor at the Free University of Berlin discovered the exact pathway for SARS-CoV-2 to enter the human brain by examining tissue samples extracted from the bodies of 32 patients who died after coronavirus.
As scientists noted, four patients died as a result of the appearance of blood clots inside the vessels in their brain. This fact led researchers to conclude that their formation was triggered by the penetration of coronavirus into the central nervous system.
Biologists later discovered that the largest number of traces of the virus were observed in the olfactory epithelium and nerve cells connecting this part of the nose to the centers of smell inside the human brain. In addition to the RNA of the virus, in favor of this was the fact that inflammatory processes, usually associated with viral infections, proceeded in these regions.
In addition, in some photographs of these cells, scientists noticed structures that were similar in size to SARS-CoV-2 particles, but at the same time different in shape. This may explain why another group of scientists from Germany could not find traces of viable particles of the virus inside the brain.
At the moment, Heppner and his team are planning to monitor exactly how COVID-19 penetrates the cells of the olfactory epithelium, which receptors it uses, and which facilitates the penetration of new viral particles into neighboring neurons.
Recall, European biologists said that SARS-CoV-2 can infect brain neurons, which over time can accelerate the development of brain diseases.
Earlier, American doctors found that the loss of smell in patients with coronavirus can be irreversible, since the olfactory receptors that go to the brain and, in fact, are the shortest path to it, “commit suicide” in order to prevent the virus from coming to it.