NEW YORK:  Researchers in the United States have discovered the mechanism that causes patients infected with Covid-19 to lose their sense of smell. The research could also offer insight on Covid-19's impact on other types of brain cells, as well as other long-term neurological effects like "brain fog," migraines, and depression.

SARS-CoV-2 infection, according to researchers from NYU Grossman School of Medicine and Columbia University, inhibits the action of olfactory receptors (OR), proteins on the surfaces of nerve cells in the nose that detect chemicals linked with odours.

Experiments revealed that when the virus was found near nerve cells (neurons) in olfactory tissue, immune cells such as microglia and T cells rushed in to sense and counter the infection. Even though the virus cannot infect them, such cells release chemicals called cytokines, which alter the genetic activity of olfactory nerve cells, according to the researchers.

"Our findings provide the first molecular explanation of smell loss in Covid-19 and how this may underpin extended Covid-19 biology," said Benjamin, an NYU Langone Health professor of microbiology. "The research also explains how a pandemic virus that infects less than 1% of human cells may cause such significant harm to so many organs," he added.

Covid Roundup: India reports 1.72 lakh new cases, TPR 10.99 pc

Zydus Cadila Dispatches first consignment of Covid vaccine to Centre

WHO advises countries to ease Covid measures' slowly and steadily'