scholarly journals An antiserum specific for cholinergic synaptic vesicles from electric organ.

1980 ◽  
Vol 87 (1) ◽  
pp. 98-103 ◽  
Author(s):  
S S Carlson ◽  
R B Kelly

Rabbit antisera to highly purified synaptic vesicles from the electric organ of Narcine brasiliensis, an electric ray, reveal a unique population of synaptic vesicle antigens in addition to a population shared with other electric organ membranes. Synaptic vesicle antigens were detected by binding successively rabbit antivesicle serum and radioactive goat anti-rabbit serum. To remove antibodies directed against antigens common to synaptic vesicles and other electric organ fractions, the antivesicle serum was extensively preadsorbed against an electric organ membrane fraction that was essentially free of synaptic vesicles. The adsorbed serum retained 40% of its ability to bind to synaptic vesicles, suggesting that about half of the antigenic determinants are unique. Vesicle antigens were quantified with a radioimmunoassay (RIA) that utilized precipitation of antibody-antigen complexes with Staphylococcus aureus cells. By this assay, the vesicles, detected by their acetylcholine (ACh) content and the antigens detected by the RIA, have the same buoyant density after isopycnic centrifugation of crude membrane fractions on sucrose and glycerol density gradients. The ratio of ACh to antigenicity was constant across the vesicle peaks and was close to that observed for vesicles purified to homogeneity. Even though the vesicles make up only approximately 0.5% of the material in the original homogenate, the ratio of acetylcholine to vesicle antigenicity could still be measured and also was indistinguishable from that of pure vesicles. We conclude that synaptic vesicles contain unique antigenic determinants not present to any measurable extent in other fractions of the electric organ. Consequently, it is possible to raise a synaptic vesicle-specific antiserum that allows vesicles to be detected and quantified. These findings are consistent with earlier immunohistochemical observations of specific antibody binding to motor nerve terminals.

2002 ◽  
Vol 88 (6) ◽  
pp. 3243-3258 ◽  
Author(s):  
You-Fen Xu ◽  
Dawn Autio ◽  
Mary B. Rheuben ◽  
William D. Atchison

Chronic treatment of rodents with 2,4-dithiobiuret (DTB) induces a neuromuscular syndrome of flaccid muscle weakness that mimics signs seen in several human neuromuscular disorders such as congenital myasthenic syndromes, botulism, and neuroaxonal dystrophy. DTB-induced muscle weakness results from a reduction of acetylcholine (ACh) release by mechanisms that are not yet clear. The objective of this study was to determine if altered release of ACh during DTB-induced muscle weakness was due to impairments of synaptic vesicle exocytosis, endocytosis, or internal vesicular processing. We examined motor nerve terminals in the triangularis sterni muscles of DTB-treated mice at the onset of muscle weakness. Uptake of FM1-43, a fluorescent marker for endocytosis, was reduced to approximately 60% of normal after either high-frequency nerve stimulation or K+depolarization. Terminals ranged from those with nearly normal fluorescence (“bright terminals”) to terminals that were poorly labeled (“dim terminals”). Ultrastructurally, the number of synaptic vesicles that were labeled with horseradish peroxidase (HRP) was also reduced by DTB to approximately 60%; labeling among terminals was similarly variable. A subset of DTB-treated terminals having abnormal tubulovesicular profiles in their centers did not respond to stimulation with increased uptake of HRP and may correspond to dim terminals. Two findings suggest that posttetanic “slow endocytosis” remained qualitatively normal: the rate of this type of endocytosis as measured with FM1-43 did not differ from normal, and HRP was observed in organelles associated with this pathway- coated vesicles, cisternae, as well as synaptic vesicles but not in the tubulovesicular profiles. In DTB-treated bright terminals, end-plate potential (EPP) amplitudes were decreased, and synaptic depression in response to 15-Hz stimulation was increased compared with those of untreated mice; in dim terminals, EPPs were not observed during block withd-tubocurarine. Nerve-stimulation-induced unloading of FM1-43 was slower and less complete than normal in bright terminals, did not occur in dim terminals, and was not enhanced by α-latrotoxin. Collectively, these results indicate that the size of the recycling vesicle pool is reduced in nerve terminals during DTB-induced muscle weakness. The mechanisms by which this reduction occurs are not certain, but accumulated evidence suggests that they may include defects in either or both exocytosis and internal vesicular processing.


1973 ◽  
Vol 57 (2) ◽  
pp. 315-344 ◽  
Author(s):  
J. E. Heuser ◽  
T. S. Reese

When the nerves of isolated frog sartorius muscles were stimulated at 10 Hz, synaptic vesicles in the motor nerve terminals became transiently depleted. This depletion apparently resulted from a redistribution rather than disappearance of synaptic vesicle membrane, since the total amount of membrane comprising these nerve terminals remained constant during stimulation. At 1 min of stimulation, the 30% depletion in synaptic vesicle membrane was nearly balanced by an increase in plasma membrane, suggesting that vesicle membrane rapidly moved to the surface as it might if vesicles released their content of transmitter by exocytosis. After 15 min of stimulation, the 60% depletion of synaptic vesicle membrane was largely balanced by the appearance of numerous irregular membrane-walled cisternae inside the terminals, suggesting that vesicle membrane was retrieved from the surface as cisternae. When muscles were rested after 15 min of stimulation, cisternae disappeared and synaptic vesicles reappeared, suggesting that cisternae divided to form new synaptic vesicles so that the original vesicle membrane was now recycled into new synaptic vesicles. When muscles were soaked in horseradish peroxidase (HRP), this tracerfirst entered the cisternae which formed during stimulation and then entered a large proportion of the synaptic vesicles which reappeared during rest, strengthening the idea that synaptic vesicle membrane added to the surface was retrieved as cisternae which subsequently divided to form new vesicles. When muscles containing HRP in synaptic vesicles were washed to remove extracellular HRP and restimulated, HRP disappeared from vesicles without appearing in the new cisternae formed during the second stimulation, confirming that a one-way recycling of synaptic membrane, from the surface through cisternae to new vesicles, was occurring. Coated vesicles apparently represented the actual mechanism for retrieval of synaptic vesicle membrane from the plasma membrane, because during nerve stimulation they proliferated at regions of the nerve terminals covered by Schwann processes, took up peroxidase, and appeared in various stages of coalescence with cisternae. In contrast, synaptic vesicles did not appear to return directly from the surface to form cisternae, and cisternae themselves never appeared directly connected to the surface. Thus, during stimulation the intracellular compartments of this synapse change shape and take up extracellular protein in a manner which indicates that synaptic vesicle membrane added to the surface during exocytosis is retrieved by coated vesicles and recycled into new synaptic vesicles by way of intermediate cisternae.


1980 ◽  
Vol 87 (1) ◽  
pp. 104-113 ◽  
Author(s):  
J E Hooper ◽  
S S Carlson ◽  
R B Kelly

Antibodies were raised in rabbits to synaptic vesicles purified to homogeneity from the electric organ of Narcine brasiliensis, a marine electric ray. These antibodies were shown by indirect immunofluorescence techniques to bind a wide variety of nerve terminals in the mammalian nervous system, both peripheral and central. The shared antigenic determinants are found in cholinergic terminals, including the neuromuscular junction, sympathetic ganglionic and parasympathetic postganglionic terminals, and in those synaptic areas of the hippocampus and cerebellum that stain with acetylcholinesterase. They are also found in some noncholinergic regions, including adrenergic sympathetic postganglionic terminals, the peptidergic terminals in the posterior pituitary, and adrenal chromaffin cells. They are, however, not found in many noncholinergic synapse-rich regions. Such regions include the molecular layer of the cerebellum and those laminae of the dentate gyrus that receive hippocampal associational and commissural input. We conclude that one or more of the relatively small number of antigenic determinants in pure electric fish synaptic vesicles have been conserved during evolution, and are found in some but not all nerve terminals of the mammalian nervous system. The pattern of antibody binding in the central nervous system suggests unexpected biochemical similarities between nerve terminals heretofore regarded as unrelated.


1974 ◽  
Vol 187 (1087) ◽  
pp. 235-241 ◽  

Non-heated rabbit serum causes massive transmitter release from motor nerve endings. The effect is not observed after heating the serum, in the way usually done to destroy complement. It seems that serum may be acting on the nerve terminals by a mechanism involving the complement system in the absence of antibody.


PLoS ONE ◽  
2011 ◽  
Vol 6 (10) ◽  
pp. e26164 ◽  
Author(s):  
Laura Torres-Benito ◽  
Margret Feodora Neher ◽  
Raquel Cano ◽  
Rocio Ruiz ◽  
Lucia Tabares

1981 ◽  
Vol 59 (3) ◽  
pp. 364-369
Author(s):  
R. L. Crabtree ◽  
R. G. Sherman

Excitatory and inhibitory neuromuscular synapses in the thoracic deep flexors of the crayfish were examined using electron microscopy. Excitatory nerve terminals were found to have larger synaptic vesicles and a greater synaptic cleft distance than did inhibitory terminals. These results were confirmed by fixation enhancement of differences in synaptic vesicle morphology and the experimental depletion of vesicles in the excitatory nerve terminals.


Author(s):  
M. Reinecke ◽  
Ch. Walther

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.


2006 ◽  
Vol 100 (2) ◽  
pp. 662-671 ◽  
Author(s):  
S. Logsdon ◽  
A. F. M. Johnstone ◽  
K. Viele ◽  
R. L. Cooper

The reserve pool (RP) and readily releasable pool (RRP) of synaptic vesicles within presynaptic nerve terminals were physiologically differentiated into distinctly separate functional groups. This was accomplished in glutamatergic nerve terminals by blocking the glutamate transporter with dl-threo-β-benzyloxyaspartate (TBOA; 10 μM) during electrical stimulation with either 40 Hz of 10 pulses within a train or 20- or 50-Hz continuous stimulation. The 50-Hz continuous stimulation decreased the excitatory postsynaptic potential amplitude 60 min faster than for the 20-Hz continuous stimulation in the presence of TBOA ( P < 0.05). There was no significant difference between the train stimulation and 20-Hz continuous stimulation in the run-down time in the presence of TBOA. After TBOA-induced synaptic depression, the excitatory postsynaptic potentials were rapidly (<1 min) revitalized by exposure to serotonin (5-HT, 1 μM) in every preparation tested ( P < 0.05). At this glutamatergic nerve terminal, 5-HT promotes an increase probability of vesicular docking and fusion. Quantal recordings made directly at nerve terminals revealed smaller quantal sizes with TBOA exposure with a marked increase in quantal size as well as a continual appearance of smaller quanta upon 5-HT treatment after TBOA-induced depression. Thus 5-HT was able to recruit vesicles from the RP that were not rapidly depleted by acute TBOA treatment and electrical stimulation. The results support the notion that the RRP is selectively activated during rapid electrical stimulation sparing the RP; however, the RP can be recruited by the neuromodulator 5-HT. This suggests at least two separate kinetic and distinct regulatory paths for vesicle recycling within the presynaptic nerve terminal.


1996 ◽  
Vol 133 (6) ◽  
pp. 1237-1250 ◽  
Author(s):  
K Takei ◽  
O Mundigl ◽  
L Daniell ◽  
P De Camilli

Strong evidence implicates clathrin-coated vesicles and endosome-like vacuoles in the reformation of synaptic vesicles after exocytosis, and it is generally assumed that these vacuoles represent a traffic station downstream from clathrin-coated vesicles. To gain insight into the mechanisms of synaptic vesicle budding from endosome-like intermediates, lysed nerve terminals and nerve terminal membrane subfractions were examined by EM after incubations with GTP gamma S. Numerous clathrin-coated budding intermediates that were positive for AP2 and AP180 immunoreactivity and often collared by a dynamin ring were seen. These were present not only on the plasma membrane (Takei, K., P.S. McPherson, S.L.Schmid, and P. De Camilli. 1995. Nature (Lond.). 374:186-190), but also on internal vacuoles. The lumen of these vacuoles retained extracellular tracers and was therefore functionally segregated from the extracellular medium, although narrow connections between their membranes and the plasmalemma were sometimes visible by serial sectioning. Similar observations were made in intact cultured hippocampal neurons exposed to high K+ stimulation. Coated vesicle buds were generally in the same size range of synaptic vesicles and positive for the synaptic vesicle protein synaptotagmin. Based on these results, we suggest that endosome-like intermediates of nerve terminals originate by bulk uptake of the plasma membrane and that clathrin- and dynamin-mediated budding takes place in parallel from the plasmalemma and from these internal membranes. We propose a synaptic vesicle recycling model that involves a single vesicle budding step mediated by clathrin and dynamin.


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