Doory
Ultrafast endocytosis at mouse hippocampal synapses
Nature 504, 2013
Background
- lab previously published correlative EM
- Combine optogentics and high-pressure freezing ‘flash and freeze’, to study synapse.
- 40 nm EM sections
- methods of exocytosis
- full fusion (vesicle fuses and releases)
- kiss and run – transient fusion, partial release of cargo, partial transfer of membrane?, vesicle still exists
- methods of endocytosis
- clathrin mediated
- ‘kiss and run’ – transient fusion reverses, (some membrane transfered to vesicle? some cargo endocytosed from outside during transient fusion?)
Observation
- Docked vesicles fuse in the active zone.
- estimate number of vesicles exchanged per synapse per stimulation (?)
- Endocytosis peaks at 100 ms (judged by size and by incorporation of a fluid label).
- exocytosis in the active zone, endocytosis at the periphery.
- show that actin is requried from endocytosis.
- Dynamin is required for proper cleavage of endcytosis events.
- no evidence of intermediate size vesicles (kiss and run).
Main conclusion
- endocytosis recycling at synapses is occurring much faster than previously believed (100 ms)