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Examination of Synaptic Vesicle Recycling Using FM Dyes During Evoked, Spontaneous, and Miniature Synaptic Activities
Published on: March 31, 2014
Dynamin and activity regulate synaptic vesicle recycling in sympathetic neurons
Wenbo Lu1, Huan Ma, Zu-Hang Sheng
1Department of Neurobiology, School of Medicine, Shanghai Jiao Tong University, Shanghai 200025, China.
The Journal of Biological Chemistry
|November 18, 2008
Summary
This study reveals two distinct modes of synaptic vesicle recycling in neurons, mediated by dynamin. Dynasore and a dynamin peptide differentially affect synaptic transmission, highlighting activity-dependent and independent pathways for vesicle replenishment.
Area of Science:
- Neuroscience
- Cell Biology
- Synaptic Physiology
Background:
- Synaptic vesicle recycling is crucial for neurotransmission.
- Endocytosis replenishes the vesicle pool for sustained synaptic function.
Purpose of the Study:
- To investigate the kinetics and molecular mechanisms of synaptic vesicle recycling modes.
- To differentiate activity-dependent and independent recycling pathways at sympathetic nerve terminals.
Main Methods:
- Used superior cervical ganglion neurons in culture.
- Disrupted endocytosis using Dynasore (dynamin inhibitor) and a dynamin peptide (P4).
- Assessed synaptic transmission via excitatory postsynaptic potential responses to paired and trains of action potentials.
Main Results:
- Dynasore reduced the second response to paired pulses; P4 did not.
- Dynasore accelerated transmission reduction during high-frequency stimulation; P4 enhanced it.
- P4 delayed vesicle pool recovery post-depletion; Dynasore limited recovery to 10%.
Conclusions:
- Identified two essential modes of dynamin-mediated synaptic vesicle recycling: activity-dependent and independent.
- Demonstrated physiological and molecular heterogeneity in endocytosis at sympathetic nerve terminals.
- Provided insights into synaptic plasticity and vesicle pool replenishment.
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