Brazilian scientists have discovered evidence that the coronavirus causes a phenomenon responsible for a ripple effect on the central nervous system
A Brazilian study has identified the mechanism that may be behind the frames of depression🇧🇷 anxiety And memory loss after infection with coronavirus🇧🇷 Research provides evidence that Sars-CoV-2 affects not only neurons, but mainly astrocytes, which function as a sort of fuel pump for the brain. The phenomenon would produce a ripple effect on the central nervous system.
The long covid affects not only patients with serious diseases, but also those who have had few symptoms. In recent weeks, the country has entered a new wave of covid, associated with the Ômicron subvariants. With the increase in cases, doctors underline the importance of updating the anti-covid vaccination and guiding the use of the mask in closed and crowded environments, especially by the most vulnerable people.
“The big problem that we will experience now is the long covid, so much so that there are so many people who want to understand this disease,” said Thiago Mattar Cunha, a professor at Faculty of Medicine of Ribeirão Preto, University of São Paulo 🇧🇷USP) and co-author of the study. He says that, on one front, the researchers took biopsies from 26 fatal covid victims and collected, in addition to lung samples, brain material.
Neuronal changes were detected in five of the patients analyzed and Sars-CoV-2 was identified in the brains of all of them. “That’s when we identified astrocytes as the main virus-hosting cells in the central nervous system,” he recalls, explaining that astrocytes not only provide support to the neuron cell, but also have other supportive functions. “Any disturbance that occurs in astrocytes affects neurons in some way and, consequently, the central nervous system.
After the first observations, the researchers infected astrocytes in vitro with Sars-CoV-2 and observed that they can even produce neurotoxic substances capable of killing neurons. The group then began to observe that there may be a correlation between post-covid and memory loss, depression and anxiety, for example. “Patients with long-lasting covid have had a reduction in the mass, or size, of certain brain structures, such as the cortex, prefrontal cortex and hippocampus,” Cunha said.
The study, recently published in the scientific journal Proceedings of the National Academy of Sciences 🇧🇷PNAS), was conducted by researchers of the Campinas State University 🇧🇷unicamp) and the Federal University of Rio de Janeiro 🇧🇷UFRJ), as well as USP representatives. The analyses, which began in the first year of the pandemic, include patients affected differently by the disease.
According to research, astrocytes are susceptible to Sars-CoV-2 infection through a specific mechanism, which involves interaction with the virus’s Spike protein, a piece that attaches to human cells. As a result, energy metabolism is remodeled and this change produces a cascading effect as it affects the levels of metabolites used to fuel neurotransmitters.
another front
In a second front of the Brazilian study, conducted by Professor of Neurology at the Faculty of Medical Sciences of Unicamp Clarissa Lin Yasuda, 81 volunteers were analyzed, who had mild or moderate cases of covid. The patients were evaluated approximately two months after infection.
“What we saw in the group (that had gotten infected) is that people were showing a lot of symptoms of anxiety and depression, as well as complaints of tiredness and sleepiness,” Clarissa explained. According to the study, a morphometric analysis of these individuals, based on cortical surface area, was performed and the results were compared with those of 81 healthy volunteers with no comorbidities.
The researcher says that she also performed a battery of cognitive tests on part of the group and that it was observed that most of the patients had impairments in memory and other domains of cognition, such as visual control. “What scares us is that these individuals (analysed) averaged 15 years of schooling. Even so, they had complaints, and when we went to measure cognition, there was impairment,” she points out.
The study points out that although growing evidence confirms neuropsychiatric manifestations associated primarily with severe cases, long-term neuropsychiatric dysfunction, called long-term covid, has also been frequently observed after mild cases.
According to the survey, neurological symptoms would be among the most widespread extra-pulmonary complications of covid: they affected over 30% of the patients analysed. Further research is needed to better understand the impact of post-covid (it is not clear in what percentage of patients it occurs, for example), but the results draw attention to the need for prevention, even in a scenario where cases They are few. evolving in serious conditions.
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Source: Terra
Ben Stock is a lifestyle journalist and author at Gossipify. He writes about topics such as health, wellness, travel, food and home decor. He provides practical advice and inspiration to improve well-being, keeps readers up to date with latest lifestyle news and trends, known for his engaging writing style, in-depth analysis and unique perspectives.
