Obese mice lose anxiety when 'zombie cells' exit their brain

Mayo Clinic researchers and collaborators have shown in mice that obesity increases the level of "zombie" or senescent cells in the brain, and that those cells, in turn, are linked to anxiety. When senolytic drugs are used to clear those cells, the anxious behaviors in the mice dissipate. These findings appear in Cell Metabolism. Senscent cells are just as the name zombie implies—semidormant cells that remain in a given area of the body and, by doing so, impair other functions. Research has shown that they contribute to aspects of aging, from osteoporosis to diabetes and muscle weakness. In this case, researchers knew that obesity—in both humans and mice—is related to increased anxiety and other emotional issues. Yet the details of that relationship are unclear.
Using genetically modified mice and normal mice, the team, which included researchers from the Mayo Clinic Robert and Arlene Kogod Center on Aging and the University of Newcastle, as well as others, determined that the study mice developed more fat cells in the brain area that controls anxiety and they had a significant increase of senescent cells in that region. Clearing the cells with senolytic drugs in the two mouse models resulted in anxious behavior ending; lipid cells in the brain disappearing; and neurogenesis, or normal neurological cell growth, resuming.