Alva G Sainz, Xinnan Wang
Mitochondria are not uniform organelles. Across the brain, they exhibit profound molecular, biochemical, and functional diversity shaped by cell type, anatomical region, subcellular compartment, and lived experience. Recent advances in cell-type- and subcellular domain-targeted proteomics, transcriptomics, advanced live imaging, and functional biochemistry have begun to map this landscape with unprecedented resolution. Together, these findings challenge the conventional view of mitochondria as generic metabolic engines and position mitochondrial molecular diversity as a fundamental feature of brain organization, with direct relevance to behavior, aging, and neurological disease. This mini review synthesizes key recent studies in this field, highlighting their findings, methodological novelty, and significance, and formulates theories and hypotheses for future investigations.