TY - JOUR TI - Optical detection of three modes of endocytosis at hippocampal synapses AU - Chanaday, Natali L AU - Kavalali, Ege T A2 - Brunger, Axel T VL - 7 PY - 2018 DA - 2018/04/23 SP - e36097 C1 - eLife 2018;7:e36097 DO - 10.7554/eLife.36097 UR - https://doi.org/10.7554/eLife.36097 AB - Coupling of synaptic vesicle fusion and retrieval constitutes a core mechanism ensuring maintenance of presynaptic function. Recent studies using fast-freeze electron microscopy and capacitance measurements reported an ultrafast mode of endocytosis operating at physiological temperatures. Here, using rat hippocampal neurons, we optically monitored single synaptic vesicle endocytosis with high time resolution using the vesicular glutamate transporter, synaptophysin and the V0a1 subunit of the vacuolar ATPase as probes. In this setting, we could distinguish three components of retrieval operating at ultrafast (~150–250 ms, ~20% of events), fast (~5–12 s, ~40% of events) and ultraslow speeds (>20 s, ~40% of events). While increasing Ca2+ slowed the fast events, increasing temperature accelerated their time course. In contrast, the kinetics of ultrafast events were only mildly affected by these manipulations. These results suggest that synaptic vesicle proteins can be retrieved with ultrafast kinetics, although a majority of evoked fusion events are coupled to slower retrieval mechanisms. KW - synaptic vesicle recycling KW - synaptic terminals KW - temperature KW - endocytosis KW - single vesicle release KW - neuroscience JF - eLife SN - 2050-084X PB - eLife Sciences Publications, Ltd ER -