Polarized mitochondrial respiratory chain complexes in synaptic mitochondria induced by plasticity signals.

Mitochondria are well established as key supporters of synaptic plasticity, yet the nanoscale spatial distribution of specific mitochondrial membrane proteins during this process remains poorly understood. Using 3D MINFLUX nanoscopy, we investigated their polarized distribution within synapses of cortical neurons undergoing chemical long-term potentiation (cLTP). Upon cLTP induction in DIV17 neurons, we observed an increased mitochondrial occupancy in stimulated synapses. Respiratory complexes of the inner mitochondrial membrane (IMM)-such as COX-IV and SDHA-showed a polarized accumulation near presynaptic sites, as validated by cluster analysis and 3D mapping. By contrast, outer mitochondrial membrane (OMM) proteins, including TOMM20 and VDAC, exhibited no significant polarized distribution. Together, these results demonstrate that cLTP selectively remodels the inner mitochondrial membrane to address localized energy requirements, highlighting the power of 3D MINFLUX for resolving protein organization with subcellular precision.