Polarized ATP synthase in synaptic mitochondria induced by learning and plasticity signals

MINFLUX represents a state-of-the-art single-molecule localization microscopy technology that surpasses the conventional diffraction limit, enabling the visualization and analysis of nanostructures with exceptional precision. Despite its potential, the utilization of MINFLUX has been primarily confined to in vitro cultured cell environments. In this research, we have refined the sample preparation protocols to facilitate 3D MINFLUX imaging in fixed brain tissue sections, focusing on the mitochondrial distribution within dendritic spines and engram cells of the dentate gyrus. Probing single molecules in vivo reveals an interesting finding: the reorganization of mitochondrial inner membrane proteins during synaptic plasticity within dendritic spines of engram cells. Utilizing 3D MINFLUX nanoscopy, we identified a significant redistribution of -F1-ATP synthase, which correlates with learning related activities. This redistribution implies a pivotal function for polarized ATP synthesis in the vicinity of the postsynaptic zone, which may modulate both short-term and long-term synaptic modifications, thereby influencing synaptic plasticity and memory consolidation. Furthermore, dual-color 3D MINFLUX imaging has uncovered distinct patterns of mitochondrial reorganization involving both the inner and outer membranes within dendritic spines. These patterns, induced by plasticity signals, persist for up to 12 hours in neuronal cultures. This distinction highlights the presence of distinct regulatory mechanisms governing mitochondrial proteins during synaptic plasticity. These results offer new insights into the molecular mechanisms underlying synaptic plasticity and underscore the transformative potential of 3D MINFLUX imaging for studying neuronal processes in the brain.