scholarly journals Loss of synaptic vesicles from neuromuscular junctions in aged MRF4-null mice

Neuroreport ◽  
2011 ◽  
Vol 22 (4) ◽  
pp. 185-189 ◽  
Author(s):  
Qingbo Wang ◽  
Sadie L. Hebert ◽  
Mark M. Rich ◽  
Susan D. Kraner
Keyword(s):  
Synaptic Vesicles ◽  
Neuromuscular Junctions

Structural and functional changes of frog neuromuscular junctions in high calcium solutions

1971 ◽  
Vol 178 (1053) ◽  
pp. 407-415 ◽  
Keyword(s):  
Transmitter Release ◽  
Synaptic Vesicles ◽  
Neuromuscular Junctions ◽  
Motor Nerve ◽  
Secretory Response ◽  
Spontaneous Release ◽  
Functional Changes ◽  
High Calcium ◽  
Release Of Acetylcholine ◽  
Evoked Transmitter Release

When frog muscles are exposed for several hours to a solution of isotonic calcium chloride, the secretory response of the motor nerve terminals to imposed depolarization ultimately fails and the rate of spontaneous release of acetylcholine also declines towards zero. The failure of depolarization-evoked transmitter release is irreversible while spontaneous release reappears, though in highly abnormal fashion, when the muscle is returned to a normal ionic medium. Examination of motor end-plates, during various stages of calcium treatment, shows that there is gradual intra-axonal agglutination of synaptic vesicles which is only very incompletely reversible. This effect is presumably the consequence of gradual entry and intracellular accumulation of calcium ions. Analogous treatment with isotonic magnesium, while resulting in immediate loss of evoked transmitter release, does not lead to progressive agglutination of synaptic vesicles, nor to irreversible impairment of the secretory response of the nerve terminal. The possible relations between structural and functional changes during calcium and magnesium treatment are discussed.

scholarly journals UPTAKE OF EXOGENOUS HORSERADISH PEROXIDASE BY COATED VESICLES IN MOUSE NEUROMUSCULAR JUNCTIONS

1969 ◽  
Vol 17 (3) ◽  
pp. 161-170 ◽  
Author(s):  
SUMNER I. ZACKS ◽  
ATUSHI SAITO
Keyword(s):  
Skeletal Muscle ◽  
Horseradish Peroxidase ◽  
Synaptic Vesicles ◽  
Intramuscular Injection ◽  
Neuromuscular Junctions ◽  
Neuromuscular Function ◽  
Coated Vesicles ◽  
Intramuscular Nerves ◽  
Pinocytotic Vesicles ◽  
Intercellular Clefts

Following intramuscular injection of horseradish peroxidase into mouse skeletal muscle adjacent to areas of innervation, rapid uptake of the label was observed by coated but not synaptic vesicles. The tracer was also found in Schwann cells, external mesaxons and within peripheral myelin lamellae, but never in axoplasm of intramuscular nerves proximal to the injection site. The data suggest that the tracer is taken up by the coated vesicles and may be rapidly discharged into the synaptic clefts from which it is cleared by a combination of phagocytic activity and absorption via pinocytotic vesicles and intercellular clefts of adjacent capillaries or, more probably, enzyme activity is lost within the coated vesicles. The significance of these observations as related to neuromuscular function is discussed.

scholarly journals Ca2+–Calmodulin regulates SNARE assembly and spontaneous neurotransmitter release via v-ATPase subunit V0a1

2014 ◽  
Vol 205 (1) ◽  
pp. 21-31 ◽  
Author(s):  
Dong Wang ◽  
Daniel Epstein ◽  
Ossama Khalaf ◽  
Sankaranarayanan Srinivasan ◽  
W. Ryan Williamson ◽  
...  
Keyword(s):  
Synaptic Vesicles ◽  
Neuromuscular Junctions ◽  
Snare Complex ◽  
Dependent Manner ◽  
Spontaneous Release ◽  
Attachment Protein ◽  
Atpase Subunit ◽  
Protein Receptor ◽  
Vesicle Exocytosis ◽  
Cam Regulation

Most chemical neurotransmission occurs through Ca2+-dependent evoked or spontaneous vesicle exocytosis. In both cases, Ca2+ sensing is thought to occur shortly before exocytosis. In this paper, we provide evidence that the Ca2+ dependence of spontaneous vesicle release may partly result from an earlier requirement of Ca2+ for the assembly of soluble N-ethylmaleimide–sensitive fusion attachment protein receptor (SNARE) complexes. We show that the neuronal vacuolar-type H+-adenosine triphosphatase V0 subunit a1 (V100) can regulate the formation of SNARE complexes in a Ca2+–Calmodulin (CaM)-dependent manner. Ca2+–CaM regulation of V100 is not required for vesicle acidification. Specific disruption of the Ca2+-dependent regulation of V100 by CaM led to a >90% loss of spontaneous release but only had a mild effect on evoked release at Drosophila melanogaster embryo neuromuscular junctions. Our data suggest that Ca2+–CaM regulation of V100 may control SNARE complex assembly for a subset of synaptic vesicles that sustain spontaneous release.

scholarly journals Ultrafast endocytosis at Caenorhabditis elegans neuromuscular junctions

eLife ◽  
2013 ◽  
Vol 2 ◽  
Author(s):  
Shigeki Watanabe ◽  
Qiang Liu ◽  
M Wayne Davis ◽  
Gunther Hollopeter ◽  
Nikita Thomas ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Motor Neurons ◽  
Synaptic Vesicles ◽  
Neuromuscular Junctions ◽  
Light Stimulus ◽  
Single Stimulus ◽  
Vesicle Recycling ◽  
Ultrastructural Studies ◽  
Millisecond Time Scale ◽  
Intense Stimulation

Synaptic vesicles can be released at extremely high rates, which places an extraordinary demand on the recycling machinery. Previous ultrastructural studies of vesicle recycling were conducted in dissected preparations using an intense stimulation to maximize the probability of release. Here, a single light stimulus was applied to motor neurons in intact Caenorhabditis elegans nematodes expressing channelrhodopsin, and the animals rapidly frozen. We found that docked vesicles fuse along a broad active zone in response to a single stimulus, and are replenished with a time constant of about 2 s. Endocytosis occurs within 50 ms adjacent to the dense projection and after 1 s adjacent to adherens junctions. These studies suggest that synaptic vesicle endocytosis may occur on a millisecond time scale following a single physiological stimulus in the intact nervous system and is unlikely to conform to current models of endocytosis.

scholarly journals Reversible alteration in the neuromuscular junctions of Drosophila melanogaster bearing a temperature-sensitive mutation, shibire.

1979 ◽  
Vol 81 (3) ◽  
pp. 520-527 ◽  
Author(s):  
C A Poodry ◽  
L Edgar
Keyword(s):  
Drosophila Melanogaster ◽  
Temperature Change ◽  
Synaptic Vesicles ◽  
Neuromuscular Junctions ◽  
Prior Treatment ◽  
Temperature Sensitive ◽  
Large Numbers ◽  
Temperature Sensitive Mutation

In this study we report a relationship between the ultrastruct of the neuromuscular junctions of tibial muscles and the temperature-induced paralysis in shibire flies. There is a decrease in the number of synaptic vesicles of neuromuscular junctions in flies which are held at or above 29 degrees. Shortly after return to 22 degrees C, the synaptic vesicles are again present in large numbers. Prior treatment with tetrodotoxin or barbiturate protects the junctions from the temperature change in morphology.

Zinc iodide-osmium tetroxide reaction: its effect on the synaptic vesicles in locust neuromuscular junctions and its chemical basis

1978 ◽  
Vol 36 (2) ◽  
pp. 614-615
Author(s):  
M. Reinecke ◽  
Ch. Walther
Keyword(s):  
Synaptic Vesicles ◽  
Osmium Tetroxide ◽  
Neuromuscular Junctions ◽  
Motor Nerve ◽  
Locusta Migratoria ◽  
Nerve Terminals ◽  
Neurobiological Research ◽  
Zinc Iodide ◽  
Electron Lucent

The zinc iodide-osmium tetroxide reaction (ZIO) was first used in neurobiological research by Maillet (Bull. Ass. Anat. 53, 233; 1968). Subsequently several authors have shown that, under appropriate conditions, ZIO stains mainly the interior of synaptic vesicles. The substrate of this reaction is under discussion, since ZIO can also react with other subcellular structures in a variety of tissues, e. g. mitochondria, endoplasmic reticulum, dictyosomes and lysosomes. Additionally, in vitro substances as different as some aminoacids, catecholamines, aldehydes and phospholipids (Pellegrino de Iraldi, Experientia 33, 1; 1977) can yield black precipitations with ZIO.Our studies were done with the motor nerve terminals at the femoral retractor unguis muscle of the locust (Locusta migratoria). These terminals are chiefly the endings of excitatory motoraxons and are characterized by the presence of electron lucent vesicles and by an accumulation of mitochondria.

Investigations of the Relationship Between Acetylcholine Synthesis and the Recycling of Synaptic Vesicles

1976 ◽  
Vol 34 ◽  
pp. 4-5
Author(s):  
Francine M. Benes ◽  
Russell J. Barrnett
Keyword(s):  
Synaptic Vesicles ◽  
Neuromuscular Junctions ◽  
Synaptic Membrane ◽  
Frog Neuromuscular Junction ◽  
Acetylcholine Synthesis ◽  
The Reformation ◽  
Key Factor ◽  
Choline Acetylase ◽  
Series Of Experiments ◽  
Biochemical Analyses

It is well established that synaptic vesicles fuse with the pre-synaptic membrane during stimulation, and are reformed during a period of rest. These events have been correlated with the depletion and resynthesis of stores of acetylcholine (Ach) in the frog neuromuscular junction. Thus, choline acetylase (ChAc) activity appears to be a key factor in the metabolism of the transmitter Ach pool. The present work inquires into the possible interrelationship of the above events; that is, whether the reformation of vesicles after depletion by stimulation is associated with the activity of ChAc. Therefore, a series of experiments on frog neuromuscular junctions were performed in which the data from biochemical analyses of acetylcholine synthesis and from the morphometric determination of vesicle numbers were compared.

Depletion of synaptic vesicles at the frog (Rana pipiens) neuromuscular junctions by tetraphenylboron

1976 ◽  
Vol 32 (11) ◽  
pp. 1423-1426 ◽  
Author(s):  
I. G. Marshall ◽  
R. L. Parsons ◽  
W. K. Paull
Keyword(s):  
Synaptic Vesicles ◽  
Rana Pipiens ◽  
Neuromuscular Junctions

scholarly journals Macromolecular connections of active zone material to docked synaptic vesicles and presynaptic membrane at neuromuscular junctions of mouse

2009 ◽  
Vol 513 (5) ◽  
pp. 457-468 ◽  
Author(s):  
Sharuna Nagwaney ◽  
Mark Lee Harlow ◽  
Jae Hoon Jung ◽  
Joseph A. Szule ◽  
David Ress ◽  
...  
Keyword(s):  
Active Zone ◽  
Synaptic Vesicles ◽  
Neuromuscular Junctions ◽  
Presynaptic Membrane
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