Mitochondria and brain aging: From cell-specific dysfunction to intercellular cooperation

Mitochondria are essential for brain energy metabolism and are increasingly recognized as key contributors to brain aging. Although neurons are exceptionally vulnerable to age-related mitochondrial decline, emerging evidence reveals that glial and vascular cells also exhibit distinct mitochondrial impairments. This review synthesizes recent advances in our understanding of mitochondrial dysfunction across specific brain regions and diverse cell types, highlighting subcellular compartmentalization and metabolic rewiring. We further explore intercellular mitochondrial transfer as a novel form of metabolic cooperation, as well as the therapeutic potential of mitochondrial transplantation. Finally, we highlight recent clinical trials evaluating mitochondria-targeted interventions aimed at preserving brain function in older adults. Together, these findings reposition mitochondria as both integrators and amplifiers of brain aging processes across diverse cell populations. By broadening the focus beyond neurons and emphasizing translational efforts, we offer a comprehensive framework for understanding and therapeutically targeting mitochondrial dysfunction in age-related cognitive decline and neurodegeneration.