A recent study has revealed that SARS-CoV-2, the virus responsible for the COVID-19 pandemic, might be using an unexpected method to infect the brain. Researchers found that mutations in the virus’ spike protein allow it to enter brain cells through a “back door,” a process that might explain the neurological symptoms observed in some COVID-19 patients. These findings were derived from research on genetically engineered mice and could offer insights into how the virus impacts the brain.

The Role of Spike Protein Mutations

The study, published in the Nature Microbiology journal, focused on a particular part of the spike protein called the furin cleavage site. This site usually helps the virus enter cells through the “front door,” by binding to the ACE2 receptors on the cell surface. However, when this site is mutated or removed, the virus is forced to use a different route, the “back door,” to enter cells.

This alternate pathway appears to be more efficient for the virus to infect brain cells, which might explain why some COVID-19 patients experience neurological issues such as brain fog, dizziness, and memory problems.

Research Findings in Mice

Researchers conducted experiments on mice that had been genetically modified to produce human ACE2 receptors, which the virus targets to enter cells. After infecting these mice with SARS-CoV-2, the scientists analyzed the viral genomes from both lung and brain tissues. The results showed that the virus with the furin cleavage site mutation was more successful at infecting brain cells, particularly in areas related to memory and movement, like the hippocampus and premotor cortex.

Implications for Human Health

While these findings are significant, it is important to note that the study was conducted in mice, and further research is necessary to determine if the same mechanisms apply to humans. Judd Hultquist, the study’s co-author, told Live Science that scientists are keen to explore why these mutations make the virus more prone to entering the brain. Understanding this process could be crucial for developing treatments that target the neurological effects of COVID-19.

Future Research and Potential Treatments

The study opens the door to new possibilities for treating COVID-19’s impact on the brain. By identifying the pathway the virus uses to infect brain cells, researchers hope to develop drugs that can block this route. Such treatments could be especially useful in preventing long-term neurological complications associated with the virus. However, much work remains to be done to translate these findings into effective therapies for human patients.