Zombie cell research: dawn of the living dead

Researchers find that removal of ‘zombie’ cells from the brain can reduce anxiety.

Senescent, or zombie, cells are cells that no longer replicate and lie semidormant in various regions of the body, impairing regular function. The presence of these cells has been linked to aging, osteoporosis and diabetes.

Though the link between obesity and anxiety has been identified, the exact mechanism behind the association remains unclear. In a recent study, researchers from the Mayo Clinic (MN, USA) and the University of Newcastle (UK) have discovered that obese mice develop more fat cells in the region of the brain that regulates anxiety and emotions, leading to an increased number of senescent cells in that area.

Once the ‘zombie’ cells had been cleared using senolytic drugs the mice showed reduced anxious behavior. The removal of the cells led to the return of neurogenesis and a reduction in the number of lipid cells in the brain. While removal of the cells had a positive effect on psychiatry, little effect was shown in reducing overall obesity.

“Our data demonstrating a link between obesity, senescence and anxiety-like behavior provide critical support for the potential feasibility of administering senolytics to treat obesity-associated anxiety-like behavior, provided that clinical trials validate this approach,” commented the authors.

In determining anxiety, the researchers used multiple psychological research methods and behavioral tests. An anxious mouse is more likely to stay in the corner or against the wall of its enclosure, avoiding open spaces. They are also shown to be more hesitant when performing tasks such as mazes.

To gain a more detailed understanding of the role of senescent cells, more research is needed in order to determine the exact type of cells responsible and to define the mechanism by which it has an effect.