scholarly journals Astrocytes release d-serine by a large vesicle

Neuroscience ◽  
2013 ◽  
Vol 240 ◽  
pp. 243-257 ◽  
Author(s):  
N. Kang ◽  
H. Peng ◽  
Y. Yu ◽  
P.K. Stanton ◽  
T.R. Guilarte ◽  
...  
Keyword(s):  
Large Vesicle

THE PAROTOID GLAND OF THE TOAD, BUFO AMERICANUS

1956 ◽  
Vol 34 (3) ◽  
pp. 174-177 ◽  
Author(s):  
David J. McCallion
Keyword(s):  
Histological Study ◽  
Poison Gland ◽  
Glandular Epithelium ◽  
Bufo Americanus ◽  
Large Vesicle ◽  
Poison Glands ◽  
Toad Bufo

A histological study of the poison glands of the toad demonstrated that one of the components of their secretion is adrenalin or adrenalin precursor substances. The poison glands are arranged in aggregates of two or three making up the warts on the skin. Larger aggregates of poison glands on the head are the parotoid glands. Each poison gland is a large vesicle, deep in the corium of the skin, and opening through a pore in the skin by way of a conical duct. The glandular epithelium of the poison gland is a flat acellular layer of cytoplasm containing a large number of flattened nuclei. Forcibly discharged glands disintegrate, are resorbed, and are replaced by new glands regenerated from the Malpighian layer of the epidermis.

Spatial variability in release at the frog neuromuscular junction measured with FM1-43

1999 ◽  
Vol 77 (9) ◽  
pp. 672-678 ◽  
Author(s):  
L -G Wu ◽  
W J Betz
Keyword(s):  
Neuromuscular Junction ◽  
Spatial Variability ◽  
Synaptic Vesicle ◽  
Motor Nerve ◽  
Frog Neuromuscular Junction ◽  
Electron Microscopic ◽  
Electrical Nerve Stimulation ◽  
Large Vesicle ◽  
Fluorescence And Electron Microscopy ◽  
Alpha Bungarotoxin

We quantified the spatial variability in release properties at different synaptic vesicle clusters in frog motor nerve terminals, using a combination of fluorescence and electron microscopy. Individual synaptic vesicle clusters labeled with FM1-43 varied more than 10-fold in initial intensity (integrated FM1-43 fluorescence) and in absolute rate of dye loss during tetanic electrical nerve stimulation. Most of this variability arose because large vesicle clusters spanned more than one presynaptic active zone (inferred from postsynaptic acetylcholine receptor stripes labeled with rhodamine-conjugated alpha-bungarotoxin); when the rate of dye loss was normalized to the length of receptor stripe covered, variability from spot to spot was greatly reduced. In addition, electron microscopic measurements showed that large vesicle clusters (i.e., those spanning multiple active zones) were also thicker, and the increased depth of vesicles led to increased total spot fluorescence without a corresponding increase in the rate of dye loss during stimulation. These results did not reveal the presence of "hot zones" of secretory activity.Key words: synaptic transmission, exocytosis, synaptic vesicles, neuromuscular junction.

Ultrastructural and cytochemical studies on vitellogenesis in trypanorhynch cestode Dollfusiella spinulifera Beveridge, Neifar et Euzet, 2004 (Eutetrarhynchidae)

2006 ◽  
Vol 51 (3) ◽  
Author(s):  
Zdzisław Świderski ◽  
Jordi Miquel ◽  
Daniel Młocicki ◽  
Lassad Neifar ◽  
Barbara Grytner-Zięcina ◽  
...  
Keyword(s):  
Plasma Membranes ◽  
Periodic Acid ◽  
Unsaturated Lipids ◽  
Egg Formation ◽  
Large Vesicle ◽  
Cell Plasma ◽  
Shell Globule ◽  
Trypanorhynch Cestode ◽  
Flocculent Material ◽  
Glycogen Particles

AbstractThe first description of vitellogenesis in the Trypanorhyncha is presented in this paper. Though the type of vitellogenesis and mature vitellocyte in Dollfusiella spinulifera appear to be unique among the Eucestoda, to some extent they resemble that observed in the lower cestodes, namely the Tetraphyllidea and Pseudophyllidea. Maturation is characterized by: (1) an increase in cell volume; (2) extensive development of large, parallel, frequently concentric cisternae of GER that produce proteinaceous granules; (3) development of Golgi complexes engaged in packaging this material; (4) continuous enlargement of proteinaceous granules within vesicles and their transformation into shell globule clusters; and (5) progressive fusion of all vesicles, with flocculent material containing the proteinaceous granules and shell globule clusters, into a single very large vesicle that characterises mature vitellocytes of this tapeworm. Cell inclusions in and around the large vesicle consist of flocculent material of a very low density, a few shell globule clusters, moderately dense proteinaceous granules and numerous large droplets of unsaturated lipids. A new previously unreported mode of transformation of proteinaceous granules into shell globule clusters, that evidently differs from that of pseudophyllideans and tetraphyllideans, is described. Cytochemical staining with periodic acid-thiosemicarbazide-silver proteinate for polysaccharides indicates a strongly positive reaction for membrane-bound glycoproteins in all membranous structures such as GER, mitochondria, Golgi complexes, nuclear and cell plasma membranes. Similar staining revealed β-glycogen particles scattered in the cytoplasm of maturing vitellocytes. Typical cytoplasmic β-glycogen particles appear mainly during early vitellocyte maturation but it is characteristic for this species that they are only seldom visible in mature cells. Some working hypotheses concerning the interrelationship between this particular pattern of vitellogensis, possible mode of egg formation in D. spinulifera, its embryonic development and trypanorhynchean life cycle, are drawn and discussed.

scholarly journals The coiled coil domain of DEF6 facilitates formation of large vesicle-like, cytoplasmic aggregates that trap the P-body marker DCP1 and exhibit prion-like features

2019 ◽  
Author(s):  
Huaitao Cheng ◽  
Fred Sablitzky
Keyword(s):  
Conformational Change ◽  
Rho Gtpases ◽  
Immunological Synapse ◽  
Coiled Coil ◽  
Nucleotide Exchange ◽  
Ph Domain ◽  
Mutant Proteins ◽  
P Bodies ◽  
Coiled Coil Domain ◽  
Large Vesicle

ABSTRACTDEF6, also known as SLAT and IBP, is critical for the development of autoimmune disease and cancer. In T cells, DEF6 participates in TCR-mediated signalling determining T helper cell-mediated immune responses. In addition, DEF6 acts as a guanine nucleotide exchange factor for Rho GTPases facilitating F-actin assembly and stabilisation of the immunological synapse. However, DEF6 is also a component of mRNA processing bodies (P-bodies) linking it to mRNA metabolism. DEF6 can adopt multiple conformations that result in different cellular localisations and functions. Post translational modifications such as phosphorylation result in conformational change liberating functional domains that are masked in the native stage of DEF6. ITK phosphorylation of Try210/222 liberates the N-terminal end and to a certain extend also the C-terminal coiled coil domain of DEF6 resulting in P-body colocalisation. In fact, the N-terminal 45 amino acids of DEF6 that encode a Ca2+-binding EF hand are sufficient to target P-bodies. Mutant proteins that unleashed the C-terminal coiled coil domain of DEF6 spontaneously aggregated forming large vesicle-like, cytoplasmic structures. These aggregates trapped proteins such as the P-body component DCP1 altering its cytoplasmic localisation. However, cellular stress reversed aggregate formation in mutant DEF6 proteins that contained ITAM and PH domain in conjunction with the coiled coil domain resulting in colocalisation with DCP1. Furthermore, coiled coil-mediated aggregates appeared to function like prions enforcing conformational change onto wild type DEF6 protein.

scholarly journals Large Vesicle Moves in Rolling Manner by Myosin 5C along Actin Tracks

2016 ◽  
Vol 110 (3) ◽  
pp. 615a
Author(s):  
Justin J. Raupp ◽  
Alexander Pattyn ◽  
Laura K. Gunther ◽  
Xuequn Chen ◽  
Takeshi Sakamoto
Keyword(s):  
Large Vesicle

scholarly journals CHANGES IN THE SPERMATOZOON DURING FERTILIZATION IN HYDROIDES HEXAGONUS (ANNELIDA)

1961 ◽  
Vol 10 (2) ◽  
pp. 255-274 ◽  
Author(s):  
Arthur L. Colwin ◽  
Laura Hunter Colwin
Keyword(s):  
Plasma Membrane ◽  
Cross Section ◽  
Direct Contact ◽  
Plasma Membranes ◽  
Sperm Head ◽  
Vitelline Membrane ◽  
Main Body ◽  
Large Vesicle ◽  
Sperm Plasma Membrane ◽  
The Difference

This, the last of a series of three papers, deals with the final events which lead to the incorporation of the spermatozoon with the egg. The material used consisted of moderately polyspermic eggs of Hydroides hexagonus, osmium-fixed at various times up to five minutes after insemination. The first direct contact of sperm head with egg proper is by means of the acrosomal tubules. These deeply indent the egg plasma membrane, and consequently at the apex of the sperm head the surfaces of the two gametes become interdigitated. But at first the sperm and egg plasma membranes maintain their identity and a cross-section through the region of interdigitation shows these two membranes as a number of sets of two closely concentric rings. The egg plasma membrane rises to form a cone which starts to project into the hole which the spermatozoon earlier had produced in the vitelline membrane by means of lysis. But the cone does not literally engulf the sperm head. Instead, where they come into contact, sperm plasma membrane and egg plasma membrane fuse to form one continuous membranous sheet. At this juncture the two gametes have in effect become mutually incorporated and have formed a single fertilized cell with one continuous bounding membrane. At this time, at least, the membrane is a mosaic of mostly egg plasma membrane and a patch of sperm plasma membrane. The evidence indicates that the fusion of the two membranes results from vesiculation of the sperm and egg plasma membranes in the region at which they come to adjoin. Once this fusion of membranes is accomplished, the egg cytoplasm intrudes between the now common membrane and the internal sperm structures, such as the nucleus, and even extends into the flagellum; finally these sperm structures come to lie in the main body of the egg. The vesiculation suggested above appears possibly to resemble pinocytosis, with the difference that the vesicles are formed from the plasma membranes of two cells. At no time, however, is the sperm as a whole engulfed and brought to the interior of the egg within a large vesicle.

Large vesicle formation within cells induced by treatment with a mixed surfactant

Micron ◽  
1996 ◽  
Vol 27 (2) ◽  
pp. 95-105
Author(s):  
L. Packwood ◽  
E. Taylor ◽  
T.M. Storey ◽  
R. Evans-Gowing ◽  
H. Baillie-Johnson ◽  
...  
Keyword(s):  
Vesicle Formation ◽  
Mixed Surfactant ◽  
Large Vesicle
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