Effect of K+ and Na+ on calcium-dependent electron-dense particles in the monoaminergic synaptic vesicles of rat pineal nerves fixed in Ca2+-containing solutions

1983 ◽  
Vol 231 (1) ◽  
Author(s):  
Amanda Pellegrino de Iraldi ◽  
J.Pablo Corazza
Keyword(s):  
Synaptic Vesicles ◽  
Calcium Dependent ◽  
Monoaminergic Synaptic Vesicles

scholarly journals Endocytosis gets in tune with action potential bursts

eLife ◽  
2013 ◽  
Vol 2 ◽  
Author(s):  
Melissa A Herman ◽  
Christian Rosenmund
Keyword(s):  
Action Potential ◽  
Synaptic Vesicles ◽  
Calcium Dependent ◽  
Dependent Mechanism

Neurons use a calcium-dependent mechanism to optimize the rate at which synaptic vesicles are recycled.

scholarly journals Synaptic vesicles transiently dock to refill release sites

2018 ◽  
Author(s):  
Grant F Kusick ◽  
Morven Chin ◽  
Sumana Raychaudhuri ◽  
Kristina Lippmann ◽  
Kadidia P Adula ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Active Zone ◽  
Synaptic Vesicles ◽  
Electrical Field Stimulation ◽  
Dependent Manner ◽  
Single Action ◽  
Calcium Dependent ◽  
Synaptic Vesicle Exocytosis ◽  
Vesicle Exocytosis ◽  
Asynchronous Release

AbstractSynaptic vesicles fuse with the plasma membrane to release neurotransmitter following an action potential, after which new vesicles must ‘dock’ to refill vacated release sites. To capture synaptic vesicle exocytosis at cultured mouse hippocampal synapses, we induced single action potentials by electrical field stimulation then subjected neurons to high-pressure freezing to examine their morphology by electron microscopy. During synchronous release, multiple vesicles can fuse at a single active zone; this multivesicular release is augmented by increasing extracellular calcium. Fusions during synchronous release are distributed throughout the active zone, whereas fusions during asynchronous release are biased toward the center of the active zone. Immediately after stimulation, the total number of docked vesicles across all synapses decreases by ∼40%. Between 8 and 14 ms, new vesicles are recruited to the plasma membrane and fully replenish the docked pool in a calcium-dependent manner, but docking of these vesicles is transient and they either undock or fuse within 100 ms. These results demonstrate that recruitment of synaptic vesicles to release sites is rapid and reversible.

scholarly journals RNA editing of CAPS1 regulates synaptic vesicle organization, release and retrieval

2017 ◽  
Author(s):  
Randi J. Ulbricht ◽  
Sarah J. Sun ◽  
Claire E. DelBove ◽  
Kristina E. Kitko ◽  
Saad C. Rehman ◽  
...  
Keyword(s):  
Rna Editing ◽  
Neurotransmitter Release ◽  
Synaptic Vesicles ◽  
Hippocampal Neurons ◽  
Protein Isoforms ◽  
Editing Event ◽  
Calcium Dependent ◽  
Presynaptic Vesicle ◽  
Vesicle Pool ◽  
Fine Tune

ABSTRACTCalcium-dependent activator protein for secretion 1 (CAPS1) facilitates the docking and priming of synaptic and dense core vesicles. A conserved hairpin structure in the CAPS1 pre-mRNA allows an post-transcriptional adenosine-to-inosine RNA editing event to alter a genomically-encoded glutamate to a glycine codon. Functional comparisons of CAPS1 protein isoforms in primary hippocampal neurons show that elevation of edited CAPS1 isoforms facilitates presynaptic vesicle clustering and turnover. Conversely, non-edited CAPS1 isoforms slow evoked release, increase spontaneous fusion, and loosen the clustering of synaptic vesicles. Therefore, CAPS1 editing promotes organization of the vesicle pool in a way that is beneficial for evoked release, while non-edited isoforms promote more lax vesicle organization that widens distribution, attenuates evoked release and eases the control of spontaneous fusion. Overall, RNA editing of CAPS1 is a mechanism to fine tune neurotransmitter release.IMPACT STATEMENTPost-transcriptional RNA editing of CAPS1 is a mechanism to regulate neurotransmitter release from synaptic vesicles.

Autoradiographic Distribution of the Eye Monoaminergic Synaptic Vesicles

1994 ◽  
Vol 26 (4) ◽  
pp. 232-239
Author(s):  
Philippe Denis ◽  
Jean-Philippe Nordmann ◽  
Daniel Scherman ◽  
Henry Saraux ◽  
William Rostène
Keyword(s):  
Synaptic Vesicles ◽  
Monoaminergic Synaptic Vesicles

scholarly journals Synapsin I (protein I), a nerve terminal-specific phosphoprotein. III. Its association with synaptic vesicles studied in a highly purified synaptic vesicle preparation.

1983 ◽  
Vol 96 (5) ◽  
pp. 1374-1388 ◽  
Author(s):  
W B Huttner ◽  
W Schiebler ◽  
P Greengard ◽  
P De Camilli
Keyword(s):  
Ionic Strength ◽  
Synaptic Vesicle ◽  
Synaptic Vesicles ◽  
Immunological Methods ◽  
Synapsin I ◽  
Tail Region ◽  
Electron Microscopic ◽  
Experimental Conditions ◽  
Calcium Dependent ◽  
Dependent Protein

Synapsin I (protein I) is a neuron-specific phosphoprotein, which is a substrate for cAMP-dependent and Ca/calmodulin-dependent protein kinases. In two accompanying studies (De Camilli, P., R. Cameron, and P. Greengard, and De Camilli, P., S. M. Harris, Jr., W. B. Huttner, and P. Greengard, 1983, J. Cell Biol. 96:1337-1354 and 1355-1373) we have shown, by immunocytochemical techniques at the light microscopic and electron microscopic levels, that synapsin I is present in the majority of, and possibly in all, nerve terminals, where it is primarily associated with synaptic vesicles. In the present study we have prepared a highly purified synaptic vesicle fraction from rat brain by a procedure that involves permeation chromatography on controlled-pore glass as a final purification step. Using immunological methods, synapsin I concentrations were determined in various subcellular fractions obtained in the course of vesicle purification. Synapsin I was found to copurify with synaptic vesicles and to represent approximately 6% of the total protein in the highly purified synaptic vesicle fraction. The copurification of synapsin I with synaptic vesicles was dependent on the use of low ionic strength media throughout the purification. Synapsin I was released into the soluble phase by increased ionic strength at neutral pH, but not by nonionic detergents. The highly purified synaptic vesicle fraction contained a calcium-dependent protein kinase that phosphorylated endogenous synapsin I in its collagenase-sensitive tail region. The phosphorylation of this region appeared to facilitate the dissociation of synapsin I from synaptic vesicles under the experimental conditions used.

Roles of ATP in Depletion and Replenishment of the Releasable Pool of Synaptic Vesicles

2002 ◽  
Vol 88 (1) ◽  
pp. 98-106 ◽  
Author(s):  
Ruth Heidelberger ◽  
Peter Sterling ◽  
Gary Matthews
Keyword(s):  
Synaptic Vesicles ◽  
Atp Hydrolysis ◽  
Synaptic Ribbons ◽  
Calcium Dependent ◽  
Releasable Pool ◽  
Synaptic Terminals ◽  
Active Zones ◽  
Vesicle Movement ◽  
Vesicle Pool ◽  
Secretory Apparatus

Synaptic terminals of retinal bipolar neurons contain a pool of readily releasable synaptic vesicles that undergo rapid calcium-dependent release. ATP hydrolysis is required for the functional refilling of this vesicle pool. However, it was unclear which steps required ATP hydrolysis: delivery of vesicles to their anatomical release sites or preparation of synaptic vesicles and/or the secretory apparatus for fusion. To address this, we dialyzed single synaptic terminals with ATP or the poorly hydrolyzable analogue ATP-γS and examined the size of the releasable pool, refilling of the releasable pool, and the number of vesicles at anatomical active zones. After minutes of dialysis with ATP-γS, vesicles already in the releasable pool could still be discharged. This pool was not functionally refilled despite the fact that its anatomical correlate, the number of synaptic vesicles tethered to active zone synaptic ribbons, was completely normal. We conclude 1) because the existing releasable pool is stable during prolonged inhibition of ATP hydrolysis, whereas entry into the functional pool is blocked, a vesicle on entering the pool will tend to remain there until it fuses; 2) because the anatomical pool is unaffected by inhibition of ATP hydrolysis, failure to refill the functional pool is not caused by failure of vesicle movement; 3) local vesicle movements important for pool refilling and fusion are independent of conventional ATP-dependent motor proteins; and 4) ATP hydrolysis is required for the biochemical transition of vesicles and/or release sites to fusion-competent status.

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