scholarly journals ON DIFFERENT TYPES OF SYNAPTIC VESICLES IN THE SYMPATHETIC GANGLIA OF AMPHIBIA

1964 ◽  
Vol 14 (2) ◽  
pp. 210-219 ◽  
Author(s):  
Koji UCHIZONO
Keyword(s):  
Synaptic Vesicles ◽  
Sympathetic Ganglia ◽  
Different Types

scholarly journals SOME FEATURES OF THE SUBMICROSCOPIC MORPHOLOGY OF SYNAPSES IN FROG AND EARTHWORM

1955 ◽  
Vol 1 (1) ◽  
pp. 47-58 ◽  
Author(s):  
Eduardo D. P. De Robertis ◽  
H. Stanley Bennett
Keyword(s):  
Electron Micrographs ◽  
Nerve Cord ◽  
Synaptic Vesicles ◽  
Sympathetic Ganglia ◽  
Synaptic Membrane ◽  
Presynaptic Membrane ◽  
Close Relationship

Electron micrographs are presented of synaptic regions encountered in sections of frog sympathetic ganglia and earthworm nerve cord neuropile. Pre- and postsynaptic neuronal elements each appear to have a membrane 70 to 100 A thick, separated from each other over the synaptic area by an intermembranal space 100 to 150 A across. A granular or vesicular component, here designated the synaptic vesicles, is encountered on the presynaptic side of the synapse and consists of numerous oval or spherical bodies 200 to 500 A in diameter, with dense circumferences and lighter centers. Synaptic vesicles are encountered in close relationship to the synaptic membrane. In the earthworm neuropile elongated vesicles are found extending through perforations or gaps in the presynaptic membrane, with portions of vesicles appearing in the intermembranal space. Mitochondria are encountered in the vicinity of the synapse, and in the frog, a submicroscopic filamentary component can be seen in the presynaptic member extending up to the region where the vesicles are found, but terminating short of the synapse itself.

scholarly journals SYNAPTIC VESICLE DEPLETION AND RECOVERY IN CAT SYMPATHETIC GANGLIA ELECTRICALLY STIMULATED IN VIVO

1974 ◽  
Vol 60 (2) ◽  
pp. 365-374 ◽  
Author(s):  
Joseph J. Pysh ◽  
Ronald G. Wiley
Keyword(s):  
Synaptic Vesicles ◽  
Surface Membrane ◽  
Complete Recovery ◽  
Sympathetic Ganglia ◽  
Vesicle Membrane ◽  
Presynaptic Terminals ◽  
Cervical Ganglion ◽  
Axodendritic Synapses ◽  
Absolute Decrease

This study examined the ultrastructure of presynaptic terminals after short periods of vigorous acetylcholine (ACh) secretion in the cat superior cervical ganglion in vivo. Experimental trunks of cats anesthetized with chloralose-urethane were stimulated supra-maximally for periods of 15–30 min and at several frequencies including the upper physiological range (5–10 Hz). Stimulated and contralateral control ganglia from each animal were fixed by intra-arterial aldehyde perfusion, processed simultaneously, and compared by electron microscopy. Stimulation produced an absolute decrease in the number of synaptic vesicles, an enlargement of axonal surface membrane, and distinct alterations in the shape of presynaptic terminals. Virtually complete recovery occurred within 1 h after stimulation at 10 Hz for 30 min. These results support the hypothesis that ACh release at mammalian axodendritic synapses occurs by exocytosis of synaptic vesicles resulting in the incorporation of vesicle membrane into the presynaptic membrane and that synaptic vesicles subsequently are reformed from plasma membrane.

Effects of temperature on coated vesicle formation within pre-synaptic terminals in cat sympathetic ganglia stimulated in vitro

1978 ◽  
Vol 36 (2) ◽  
pp. 594-595
Author(s):  
Tomoko Kadota ◽  
Ken Kadota
Keyword(s):  
Synaptic Vesicles ◽  
Uranyl Acetate ◽  
Sympathetic Ganglia ◽  
Effect Of Temperature ◽  
Coated Vesicle ◽  
Vesicle Formation ◽  
Recovery Processes ◽  
Cervical Ganglia ◽  
Ethanol Series

Many workers have shown the depletion of synaptic vesicles following nerve stimulation but there is a discrepancy among data regarding the appearance of coated vesicles attendant on the decrease in the number of synaptic vesicles (Heuser and Reese, 1973; Ceccarelli et al., 1973; Pysh and Wiley, 1974). The present experiment was an attempt to investigate the effect of temperature on stimulation dependent coated vesicle formation.Dissected cat superior cervical ganglia were incubated in Krebs solution at 10°C and 37°C respectively. Preganglionic nerves were stimulated with the electrical parameters consisting of 1 msec square pulses of 20 V at 10 Hz for 30 min. After stimulation the ganglia were fixed with 2 % 0s04 (lh). To examine the participation of the coated endocytosis on recovery processes some ganglia were stimulated at 37°C for 30 min and then rested either at 37°C or 10°C for 5 and 15 min before fixation. The fixed material were then processed for electron microscopy with conventional method consisting of uranyl acetate block stain (30 min), dehydration with ethanol series, and embedding in Epon 812.

scholarly journals Identification of a synaptic vesicle-specific membrane protein with a wide distribution in neuronal and neurosecretory tissue.

1981 ◽  
Vol 91 (1) ◽  
pp. 257-269 ◽  
Author(s):  
W D Matthew ◽  
L Tsavaler ◽  
L F Reichardt
Keyword(s):  
Synaptic Vesicles ◽  
Wide Distribution ◽  
Normal Function ◽  
Antigenic Determinants ◽  
Secretory Vesicles ◽  
Different Types ◽  
Specific Localization ◽  
Low Levels ◽  
Specific Membrane ◽  
Detectable Antigen

Two different monoclonal antibodies, characterized initially as binding synaptic terminal regions of rat brain, bind a 65,000-dalton protein, which is exposed on the outer surface of brain synaptic vesicles. Immunocytochemical experiments at the electron microscope level demonstrate that these antibodies bind the vesicles in many different types of nerve terminals. The antibodies have been used successfully to purify synaptic vesicles from crude brain homogenates by immunoprecipitation onto the surface of polyacrylamide beads. The profiles of the structures precipitated by these beads are almost exclusively vesicular, confirming the vesicle-specificity of the antibodies. In SDS gels, the antibodies bind a single protein of 65,000 daltons. The two antibodies are not identical, but compete for binding sites on this protein. Immune competition experiments also demonstrate that the antigenic components on the 65,000-dalton protein are widely distributed in neuronal and neural secretory tissues. Detectable antigen is not found in uninnervated tissue--blood cells and extrajunctional muscle. Low levels are found in nonneural secretory tissues; it is not certain whether this reflects the presence of low amounts of the antigen on all the exocytotic vesicles in these tissues or whether the antigen is found only in neuronal fibers within these tissues. The molecular weight and at least two antigenic determinants of the 65,000-dalton protein are highly conserved throughout vertebrate phylogeny. The two antibodies recognize a 65,000-dalton protein present in shark, amphibia, birds, and mammals. The highly conserved nature of the determinants on this protein and their specific localization on secretory vesicles of many different types suggest that this protein may be essential for the normal function of neuronal secretory vesicles.

scholarly journals Methods of measuring presynaptic function with fluorescence probes

2021 ◽  
Vol 51 (1) ◽  
Author(s):  
Yeseul Jang ◽  
Sung Rae Kim ◽  
Sung Hoon Lee
Keyword(s):  
Fluorescence Intensity ◽  
Neurotransmitter Release ◽  
Synaptic Vesicles ◽  
Animal Species ◽  
Fluorescence Probes ◽  
Presynaptic Function ◽  
Different Types ◽  
Species Type ◽  
Fluorescent Agent ◽  
Living Neurons

AbstractSynaptic vesicles, which are endogenous to neurotransmitters, are involved in exocytosis by active potentials and release neurotransmitters. Synaptic vesicles used in neurotransmitter release are reused via endocytosis to maintain a pool of synaptic vesicles. Synaptic vesicles show different types of exo- and endocytosis depending on animal species, type of nerve cell, and electrical activity. To accurately understand the dynamics of synaptic vesicles, direct observation of synaptic vesicles is required; however, it was difficult to observe synaptic vesicles of size 40–50 nm in living neurons. The exo-and endocytosis of synaptic vesicles was confirmed by labeling the vesicles with a fluorescent agent and measuring the changes in fluorescence intensity. To date, various methods of labeling synaptic vesicles have been proposed, and each method has its own characteristics, strength, and drawbacks. In this study, we introduce methods that can measure presynaptic activity and describe the characteristics of each technique.

Different types of synaptic vesicles in axons of the retractor penis muscle of the bull

1976 ◽  
Vol 32 (10) ◽  
pp. 1335-1337 ◽  
Author(s):  
O. Eränkö ◽  
E. Klinge ◽  
N. O. Sjöstrand
Keyword(s):  
Synaptic Vesicles ◽  
Different Types

The extinction time of a general birth and death process with catastrophes

1986 ◽  
Vol 23 (04) ◽  
pp. 851-858 ◽  
Author(s):  
P. J. Brockwell
Keyword(s):  
Laplace Transform ◽  
Size Distribution ◽  
Sufficient Conditions ◽  
Necessary And Sufficient Conditions ◽  
Death Process ◽  
Extinction Time ◽  
Birth And Death Process ◽  
Different Types ◽  
The Laplace Transform ◽  
Necessary And Sufficient

The Laplace transform of the extinction time is determined for a general birth and death process with arbitrary catastrophe rate and catastrophe size distribution. It is assumed only that the birth rates satisfyλ0= 0,λj> 0 for eachj> 0, and. Necessary and sufficient conditions for certain extinction of the population are derived. The results are applied to the linear birth and death process (λj=jλ, µj=jμ) with catastrophes of several different types.

Differentiating between different forms of moral obligations

2020 ◽  
Vol 43 ◽  
Author(s):  
Rajen A. Anderson ◽  
Benjamin C. Ruisch ◽  
David A. Pizarro
Keyword(s):  
Moral Character ◽  
Moral Obligations ◽  
Different Types

Abstract We argue that Tomasello's account overlooks important psychological distinctions between how humans judge different types of moral obligations, such as prescriptive obligations (i.e., what one should do) and proscriptive obligations (i.e., what one should not do). Specifically, evaluating these different types of obligations rests on different psychological inputs and has distinct downstream consequences for judgments of moral character.

Ultrastructural Investigations of the Contractile Filaments of Amoebae

1974 ◽  
Vol 32 ◽  
pp. 188-189
Author(s):  
P.L. Moore
Keyword(s):  
Cytoplasmic Streaming ◽  
Three Dimensional ◽  
Freeze Fracture ◽  
Amoeboid Movement ◽  
Different Types ◽  
Chemical Conditions ◽  
Complete Interpretation

Previous freeze fracture results on the intact giant, amoeba Chaos carolinensis indicated the presence of a fibrillar arrangement of filaments within the cytoplasm. A complete interpretation of the three dimensional ultrastructure of these structures, and their possible role in amoeboid movement was not possible, since comparable results could not be obtained with conventional fixation of intact amoebae. Progress in interpreting the freeze fracture images of amoebae required a more thorough understanding of the different types of filaments present in amoebae, and of the ways in which they could be organized while remaining functional.The recent development of a calcium sensitive, demembranated, amoeboid model of Chaos carolinensis has made it possible to achieve a better understanding of such functional arrangements of amoeboid filaments. In these models the motility of demembranated cytoplasm can be controlled in vitro, and the chemical conditions necessary for contractility, and cytoplasmic streaming can be investigated. It is clear from these studies that “fibrils” exist in amoeboid models, and that they are capable of contracting along their length under conditions similar to those which cause contraction in vertebrate muscles.

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