It takes just a few milliseconds: A vesicle, only a few nanometers in size and filled with neurotransmitters, approaches a cell membrane, fuses with it, and releases its chemical messengers into the synaptic cleft—making them available to bind to the next nerve cell.

A team led by Professor Christian Rosenmund of Charité—Universitätsmedizin Berlin has captured this critical moment of brain function in microscopic images. They describe their achievement in the journal Nature Communications.