Synaptic vesicle exocytosis

Existing optogenetic silencing methods affect membrane potential, biochemistry or protein integrity. Here, the authors demonstrate an approach for silencing synaptic transmission that combines fast activation and reversibility, by using nondisruptive, reversible, light-evoked clustering of synaptic vesicles, which they validate in Caenorhabditis elegans, zebrafish, and murine cell culture.

It is not fully understood if the probability of synaptic vesicle release is homogenous or varies between individual boutons. Here the authors perform optical quantal analyses of individual Schaffer collateral synapses, showing that multivesicular release enables a tenfold increase in glutamate output and that the vesicular release probability is not uniform between synapses.

This Review provides a comprehensive overview of presynaptic applications of optogenetic tools, including the associated challenges, current limitations and future directions for this approach.

Neurotransmitters can be released with a delay in relation to action potentials. This work demonstrates how this asynchronous release is related to overall vesicle release probability and short-term plasticity.