
Anna Wendt
Assistant researcher

Delay between fusion pore opening and peptide release from large dense-core vesicles in neuroendocrine cells.
Author
Summary, in English
Peptidergic neurotransmission is slow compared to that mediated by classical neurotransmitters. We have studied exocytotic membrane fusion and cargo release by simultaneous capacitance measurements and confocal imaging of single secretory vesicles in neuroendocrine cells. Depletion of the readily releasable pool (RRP) correlated with exocytosis of 10%-20% of the docked vesicles. Some remaining vesicles became releasable after recovery of RRP. Expansion of the fusion pore, seen as an increase in luminal pH, occurred after approximately 0.3 s, and peptide release was delayed by another 1-10 s. We conclude that (1) RRP refilling involves chemical modification of vesicles already in place, (2) the release of large neuropeptides via the fusion pore is negligible and only proceeds after complete fusion, and (3) sluggish peptidergic transmission reflects the time course of vesicle emptying.
Department/s
- Islet cell physiology
- Faculty of Medicine
- Diabetes - Islet Cell Exocytosis
- Division of Clinical Genetics
- Department of Clinical Sciences, Malmö
Publishing year
2002
Language
English
Pages
287-299
Publication/Series
Neuron
Volume
33
Issue
2
Links
Document type
Journal article
Publisher
Cell Press
Topic
- Neurosciences
Keywords
- Peptides/*metabolism
- PC12 Cells
- Neurosecretory Systems/cytology/*metabolism
- Membrane Fusion/*physiology
- Luminescent Proteins
- Kinetics
- Indicators and Reagents
- Hydrogen-Ion Concentration
- Exocytosis/*physiology
- Fluorescence
- Rats
- Secretory Vesicles/*metabolism
- Support
- Non-U.S. Gov't
- Electric Stimulation
- Cell Line
- Animal
Status
Published
Research group
- Islet cell physiology
- Diabetes - Islet Cell Exocytosis
ISBN/ISSN/Other
- ISSN: 0896-6273