Volume 52 Issue 3, March 2023

Despite centuries of effort from philosophers, physicians and biologists, the answer to the seemingly simple question “what is aging?” remains elusive. Some even posit that aging represents a phenomenon too expansive to ever be succinctly defined. A new study tackles this question by profiling hundreds of phenotypes across age in mice and examining how the trajectories of these phenotypes are altered by geroprotective genetic and dietary interventions.

A large number of refinements have been studied with the aim to improve rat welfare, but more evidence is needed to fully understand their impact. This mapping review draws on the findings of 1,017 studies to show that different refinements impact different rats in different ways, and that a ‘one-size-fits-all’ approach to refinements might not be appropriate.