Related Experiment Video
Updated: Jul 9, 2026
06:45
In Vivo Single-Molecule Tracking at the Drosophila Presynaptic Motor Nerve Terminal
Published on: January 14, 2018
Synaptic vesicle mobility in mouse motor nerve terminals with and without synapsin
Michael A Gaffield1, William J Betz
1Neuroscience Program, University of Colorado Medical School, Anschutz Medical Campus, Aurora, Colorado 80045, USA.
Summary
Synaptic vesicle mobility is regulated by a novel phospho-protein, not synapsin, in mouse motor nerve terminals. This protein
Area of Science:
- Neuroscience
- Cell Biology
- Biochemistry
Background:
- Synaptic vesicle mobility is crucial for neurotransmission.
- Synapsins are known regulators of synaptic vesicle pools.
- The precise molecular mechanisms governing vesicle mobility remain incompletely understood.
Purpose of the Study:
- To investigate the role of synapsins in regulating synaptic vesicle mobility.
- To identify key regulators of synaptic vesicle mobility in mouse motor nerve terminals.
- To explore the impact of temperature and pharmacological agents on vesicle dynamics.
Main Methods:
- Fluorescence recovery after photobleaching (FRAP) using FM 1-43 staining.
- Analysis of wild-type (WT) and synapsin triple knock-out (TKO) mouse motor nerve terminals.
- Pharmacological manipulation of kinase and phosphatase activity, actin cytoskeleton, and intracellular calcium.
Main Results:
- Synaptic vesicles exhibited temperature-dependent mobility, being mobile at physiological but immobile at room temperature.
- Okadaic acid (phosphatase inhibitor) increased mobility, while staurosporine (kinase inhibitor) decreased it at physiological temperature.
- Synapsin TKO mice had fewer vesicles and reduced staining but displayed normal synaptic transmission and vesicle mobility.
- Actin disruption and calcium reduction did not significantly affect mobility.
Conclusions:
- Synaptic vesicle mobility is primarily regulated by a synapsin-independent phospho-protein.
- This novel phospho-protein is a key determinant of vesicle dynamics in nerve terminals.
- Temperature significantly influences synaptic vesicle mobility, suggesting thermosensitive regulatory mechanisms.
Related Concept Videos
01:26Fusion of Secretory Vesicles with the Plasma Membrane
Proteins and neurotransmitters in secretory vesicles can be released from a cell upon vesicle docking, priming, and fusion with the plasma membrane. Vesicles are docked and primed in preparation for the quick exocytosis of their contents in response to a stimulus. The fusion process is mainly carried out by a SNAP Receptor or SNARE complex, consisting of synaptobrevin, syntaxin-1, and SNAP-25.
In 1993, Jim Rothman proposed that the antiparallel pairing of vesicular and transmembrane SNAREs, or...
In 1993, Jim Rothman proposed that the antiparallel pairing of vesicular and transmembrane SNAREs, or...
01:43The Movement of Organelles and Vesicles
In eukaryotic cells, cytoskeletal filaments such as actin, microtubules, and intermediate filaments form a mesh-like cytoskeletal network. These filaments serve as tracks for transporting cellular cargo. Specialized motor proteins use the chemical energy stored in adenosine triphosphate (ATP) for this transport. During interphase, microtubules are polarized, with the plus-end towards the cell periphery and the minus-end towards the cell center. Two microtubule-associated motor proteins,...
01:33Overview of Secretory Vesicles
Secretory vesicles, also known as dense core vesicles (DCVs), are membrane-bound vesicles that transport secretory proteins, such as hormones or neurotransmitters. Regulated secretory vesicles transport proteins from the trans-Golgi network to the exterior of the cell. Proteins present in regulated secretory vesicles are required to be rapidly exocytosed in large amounts upon a specific stimulus.
Various proteins regulate the aggregation of molecules inside the secretory vesicles. Chromogranins...
Various proteins regulate the aggregation of molecules inside the secretory vesicles. Chromogranins...
01:19The Neuromuscular Junction
The nervous system consists of complex motor neuron circuits, including upper motor neurons originating from the cerebral cortex and lower motor neurons starting in the spinal cord, coordinating both voluntary and involuntary movements. Among these, somatic motor neurons activate skeletal muscles and are classified into alpha, beta, and gamma types. Alpha neurons are vital for voluntary movement coordination, while gamma neurons adjust muscle spindle sensitivity, and the function of beta...
01:26Chemical Synapses
Chemical synapses are specialized sites between two neurons or between a neuron and a non-neuronal cell like a muscle, glandular or sensory cell.
Because chemical synapses depend on the release of neurotransmitter molecules from synaptic vesicles to pass on their signal, there is an approximately one millisecond delay between when the axon potential reaches the presynaptic terminal and when the neurotransmitter leads to opening of postsynaptic ion channels. Additionally, this signaling is...
Because chemical synapses depend on the release of neurotransmitter molecules from synaptic vesicles to pass on their signal, there is an approximately one millisecond delay between when the axon potential reaches the presynaptic terminal and when the neurotransmitter leads to opening of postsynaptic ion channels. Additionally, this signaling is...
01:26Chemical Synapses
Chemical synapses are specialized sites between two neurons or between a neuron and a non-neuronal cell like a muscle, glandular or sensory cell.
Because chemical synapses depend on the release of neurotransmitter molecules from synaptic vesicles to pass on their signal, there is an approximately one millisecond delay between when the axon potential reaches the presynaptic terminal and when the neurotransmitter leads to opening of postsynaptic ion channels. Additionally, this signaling is...
Because chemical synapses depend on the release of neurotransmitter molecules from synaptic vesicles to pass on their signal, there is an approximately one millisecond delay between when the axon potential reaches the presynaptic terminal and when the neurotransmitter leads to opening of postsynaptic ion channels. Additionally, this signaling is...