A novel designer receptor, mitoDREADD-Gs, engineered to activate stimulatory G-protein signaling within brain mitochondria, has been shown to reverse cognitive impairments in mouse models of Alzheimer’s disease and frontotemporal dementia. By boosting mitochondrial energy production, this targeted approach establishes mitochondrial dysfunction as a causal factor in neurodegeneration and offers a new therapeutic avenue. The findings, published in Nature Neuroscience by Inserm and Université de Bordeaux researchers, provide a pivotal link between mitochondrial activity and neuronal health.