Irisin promotes selective changes in hippocampal mitochondrial metabolism in mice

Irisin, an exercise-induced hormone, exerts neuroprotective actions in neurological disease models, yet its effects on brain mitochondrial metabolism remain unclear. Here, we examined how irisin influences mitochondrial function and dynamics in the mouse hippocampus. Acute irisin exposure boosted ATP-coupled oxygen consumption without altering mitochondrial content or dynamics-related proteins. Furthermore, chronic irisin administration in vivo decreased hippocampal Opa1 and Drp1 levels, two key regulators of mitochondrial remodeling. These findings uncover selective actions of irisin on hippocampal mitochondrial homeostasis and identify prolonged irisin exposure as a potential regulator of mitochondrial dynamics in the brain.