The accumulation of senescent cells, which have stopped dividing but are still metabolically active, has been linked to several illnesses, and scientists at the Mayo Clinic think they can add neurodegenerative diseases to that list. Researchers led by Darren Baker found they could reduce both physical and cognitive aspects of neurological decline in mice engineered to have aggressive neurodegenerative disease by killing off senescent astrocytes and microglial cells as they develop. (Nature 2018, DOI: 10.1038/s41586-018-0543-y). To do this, they gave the animals navitoclax, a drug already approved for treating cancer. But Baker cautions against speculating on navitoclax as a treatment for dementia or Parkinson’s disease. “This experiment was performed in the best-case scenario,” with the mice at early stages of degeneration, Baker says. How senescent cells impact neuronal health is still being figured out, he says. He adds they are now looking at how killing off senescent cells at later stages of disease affects the formation of neurofibrillary tangles, a physical hallmark of disease, and cognition.