Alzheimer’s disease is the most common type of dementia worldwide, with approximately 55 million people living with the condition. Despite the events and all the research, the cause of this pathology is still unknown; Several contributing factors have been described, but not the cause.

Now, a group of researchers at Tufts University and Oxford University have solid evidence. Common viruses may cause the onset of Alzheimer’s in the population, their results were recently published in the journal “Journal of Alzheimer’s Disease” Here we tell you the details.

Researchers began to suspect varicella zoster virus (VZV), which causes chickenpox, and herpes simplex virus type 1 (HSV-1), which causes cold sores, also known as “hot flashes” or “cold sores.” Vaccination against reactivation of VZV, which causes herpes zoster, or “shingles,” after primary chickenpox infection reduces the risk of developing Alzheimer’s.

Also, HSV-1 has previously been associated with the disease. An important coincidence in both viruses is that they can remain latent or inactive in nerve cells for years after the first infection, and then can reactivate under certain conditions, which justifies maintaining suspicion about these viruses.

In this way, the study researchers set out to evaluate the effect of nerve cells in the brain against these two viruses, for which they developed a three-dimensional model of human tissue culture with functional neurons and glial cells to mimic the brain. Along with the viruses described above.

When the brain model was infected with VZV alone, no changes were seen in the cells that showed signs of Alzheimer’s, and the infection alone caused significant inflammation.

On the other hand, when the brain model already contained dormant HSV-1, a second infection with VZV resulted in reactivation of HSV-1 and the symptoms of Alzheimer’s disease were subsequently presented, i.e., an increase in tau proteins and beta-amyloid and consequent attenuation of neuronal signals, abnormalities in brain tissue unprecedented in pathology.

“Our results suggest a pathway to Alzheimer’s disease, which is caused by VZV infection that creates inflammatory triggers in the brain that activate HSV-1. While we demonstrate a link between VZV and HSV-1 activation, other inflammatory events in the brain may also activate HSV-1 and lead to Alzheimer’s disease,” said study researcher Dana Keynes said. Communication.

As some detractors suggest Science Alert The results found are important and should continue to stimulate research, however, despite the creation of the brain model, it must be taken into account that simulating the real conditions of the brain is a great challenge, on the other hand, it is the brain inflammation itself, derived from different conditions, which lead to this condition, so other factors and microbes may be involved.

All details: Journal of Alzheimer’s Disease