China’s cutting-edge camera captures neurons ‘kissing’ in real time

Chinese scientists have resolved a 50-year neuroscience debate by capturing, for the first time, the millisecond-scale moment when neurons “kiss” — the brief contact between synaptic vesicles and the cell membrane during neurotransmitter release. Using a revolutionary imaging technology developed over 15 years, researchers from the University of Science and Technology of China (USTC) and the Shenzhen Institutes of Advanced Technology created a cryogenic electron microscopy platform capable of imaging neural activity at nanometer resolution and millisecond intervals. This time-resolved cellular cryo-electron tomography (cryo-ET) system allowed them to observe synaptic vesicle exocytosis in real time, overcoming previous limitations of traditional microscopy. Their observations revealed a unified “kiss-shrink-run” model of synaptic transmission. Within four milliseconds of activation, vesicles form a tiny fusion pore (“kiss”), then shrink to about half their surface area, and by 70 milliseconds, most vesicles detach and recycle via a “run-away” pathway,