Removing ‘zombie cells’ in the brain could help battle the effects of dementia

No, this isn’t a plot twist straight out of The Walking Dead: “Zombie cells” are a real thing, referring to cells which go into a type of suspended animation as your body gets older. Just like in any fictional zombie invasion, the longer you wait around, the more of these so-called senescent cells turn up. But here’s the good news: Stopping the accumulation of these cells could potentially help stave off or even reduce the effects of cognitive decline in the brain, including types of dementia.

“In previous studies, we and others have shown that senescent cells, which are irreversibly growth-arrest cells that acquire a distinctive pro-inflammatory phenotype, accumulate with age and at sites of pathology,” Darren Baker, a Mayo Clinic molecular biologist, who led the study, told Digital Trends. “In recent years, they have been shown to actively contribute to aging and a variety of age-related diseases. In this study, we tested whether senescent cell accumulation promoted neurodegeneration in mice.”

In their study, the researchers used a mouse model which imitated aspects of Alzheimer’s disease. This was achieved by using genetic engineering to create an altered version of the brain protein tau, which resulted in the mice losing the ability to recall new information. When the mice were given an enzyme to eliminate the buildup of senescent cells, these signs of dementia disappeared. This resulted in them regaining the ability to form memories, eliminated signs of inflammation, and more.

As exciting as this research is, however, it’s important to note that this is still early days. Science’s understanding of the exact relationship between senescent cells and human diseases is still sketchy. Baker also stressed that carrying the work over to human subjects is not in the cards for the near future.

“My laboratory is focused on the molecular understanding of senescence to aging and age-related diseases using mice as a model system,” he said. “We have shown the benefits in animals without adverse effects, but we have no idea if the same cells can be effectively or safely targeted in people.”

A paper describing the work was recently published in the journal Science.