Published May 22, 2023
| Version v1
Publication
The spatial pattern of exocytosis and post-exocytic mobility of synaptopHluorin in mouse motor nerve terminals
Contributors
Description
We monitored the spatial distribution of exo- and endocytosis at 37◦C in mouse motor nerve
terminals expressing synaptopHluorin (spH), confirming and extending earlier work at room
temperature, which had revealed fluorescent 'hot spots' appearing in repeatable locations
during tetanic stimulation. We also tested whether hot spots appeared during mild stimulation.
Averaged responses from single shocks showed a clear fluorescence jump, but revealed no sign of
hot spots; instead, fluorescence rose uniformly across the terminal. Only after 5–25 stimuli given
at high frequency did hot spots appear, suggesting a novel initiation mechanism. Experiments
showed that about half of the surface spH molecules were mobile, and that spH movement
occurred out of hot spots, demonstrating their origin as exocytic sources, not endocytic sinks.
Taken together, our results suggest that synaptic vesicles exocytose equally throughout the
terminal with mild stimulation, but preferentially exocytose at specific, repeatable locations
during tetanic stimulation.
Additional details
Identifiers
- URL
- https://idus.us.es/handle//11441/146493
- URN
- urn:oai:idus.us.es:11441/146493