Abstract
Mitochondria are central to cellular function, acting as metabolic hubs that regulate energy transduction to communicate cellular status. A key component of this energetic regulation is the mitochondrial membrane potential (MMP), a charge separation across the inner mitochondrial membrane generated by the electron transport chain. Beyond MMP's canonical role in driving ATP synthesis, MMP acts as a dynamic signaling hub. MMP rapidly adjusts to acute changes in cellular energy demand and undergoes sustained modifications during developmental processes, such as neuronal remodeling. Changes in MMP influence reactive oxygen species (ROS) production, calcium handling, and mitochondrial quality control, enabling localized and time-sensitive regulation of cellular function. In neurons, changes in MMP coordinate synaptic plasticity by linking metabolic state to structural changes at synapses. This review highlights the non-canonical roles of MMP in signal integration, spatial organization, and stress adaptation, providing a broader framework for understanding mitochondrial contributions to health and disease.