The Fine Structure of Certain Secretory Cells in the Optic Tentacles of the Snail, Helix Aspersa

1964 ◽  
Vol s3-105 (69) ◽  
pp. 35-47
Author(s):  
NANCY J. LANE
Keyword(s):  
Helix Aspersa ◽  
Secretory Cells ◽  
Multivesicular Bodies ◽  
Neurosecretory Granules ◽  
Dense Granules ◽  
Golgi Bodies ◽  
Structural Details ◽  
Snail Helix Aspersa ◽  
Electron Lucent ◽  
Dense Vesicles

In Helix aspersa, the cytoplasm of the collar cells that surround the tentacular ganglion contains spheroidal granules of low electron density (α-bodies), and β-bodies that contain electron-dense vesicles within the size range of elementary neurosecretory granules. Mitochondria and lamellar Golgi complexes are also present. Mitochondria, α-bodies, fibrils, objects resembling multivesicular bodies, and moderately electrondense granules are found in the lengthy processes into which the collar cells are drawn out. One process of each bipolar collar cell seems to merge into the tentacular ganglion. This consists of neurones with processes that contain mitochondria, vesicles of various sizes, filaments, and electron-dense granules similar to elementary neurosecretory granules. The lateral cells that line the dermo-muscular sheath encasing the optic tentacles contain in their cytoplasm an endoplasmic reticulum with many ribosomes, mitochondria, Golgi complexes, and many electron-lucent globules. These globules seem to be elaborated by the lamellar Golgi bodies. There are also electron-dense inclusions, which may be lysosomes, that are scattered sparsely between the other globules and cytoplasmic components. All these structural details are similar to those found in some mucus-secreting cells. The possible nature and origin of the tentacular secretory cells are discussed.

Two New Cell Types in the Retina of a Snail Helix aspersa

1974 ◽  
Vol 32 ◽  
pp. 284-285
Author(s):  
Jean L. Brandenburger ◽  
Richard M. Eakin
Keyword(s):  
Sensory Cell ◽  
Ganglion Cells ◽  
Common Garden ◽  
Cell Types ◽  
Helix Aspersa ◽  
Spherical Nucleus ◽  
Golgi Bodies ◽  
The Common ◽  
Snail Helix Aspersa ◽  
Electron Lucent

Previous studies have described the retina of the common garden snail Helix aspersa to be composed of two cell types: sensory and pigmented. We have now found a third, a ganglion cell, and another kind of sensory cell, both heretofore undescribed.Ganglion cells (Fig. 1) are large (11-16 fan in diameter), ovoid, and few in number. We estimate about 12 per eye. They occur only along the periphery of the retina. Each possesses a large spherical nucleus centrally situated in an electron lucent cytoplasm which contains numerous organelles and in clusions: mitochondria, Golgi bodies, EH, lysosomes, glycogen granules, microtubules, ribosomes, fine filaments and clusters of irregular vesicles. These vesicles (insert, Fig. 1) vary in size (500 A to 1200 A in diameter) and density (clear, granular or dense-cored).

Elementary Neurosecretory Granules in the Neurones of the Snail, Helix Aspersa

1964 ◽  
Vol s3-105 (69) ◽  
pp. 31-34
Author(s):  
NANCY J. LANE
Keyword(s):  
Golgi Complex ◽  
Helix Aspersa ◽  
Neurosecretory Granules ◽  
Snail Helix Aspersa

Elementary neurosecretory granules are present in the cytoplasm of certain neurones of the snail, Helix aspersa. The granules appear to be elaborated within the lamellae of the Golgi complex and produced at the edges of the lamellae by budding and vesiculation.

Histochemical and Ultrastructural Characterization of the Posterior Esophagus of Bulla striata (Mollusca, Opisthobranchia)

2010 ◽  
Vol 16 (6) ◽  
pp. 688-698 ◽  
Author(s):  
Alexandre Lobo-da-Cunha ◽  
Elsa Oliveira ◽  
Íris Ferreira ◽  
Rita Coelho ◽  
Gonçalo Calado
Keyword(s):  
Digestive System ◽  
Light And Electron Microscopy ◽  
Secretory Cells ◽  
Secretory Vesicles ◽  
Ultrastructural Characterization ◽  
Herbivorous Species ◽  
Columnar Cells ◽  
Electron Lucent ◽  
Dense Vesicles

AbstractThe posterior esophagus of Bulla striata, running from the gizzard to the stomach, was investigated with light and electron microscopy to obtain new data for a comparative analysis of the digestive system in cephalaspidean opisthobranchs. In this species, the posterior esophagus can be divided into two regions. In the first, the epithelium is formed by columnar cells with apical microvilli embedded in a cuticle. Many epithelial and subepithelial secretory cells are present in this region. In both, electron-lucent secretory vesicles containing filaments and a peripheral round mass of secretory material fill the cytoplasm. These acid mucus-secreting cells may also contain a few dense secretory vesicles. In the second part of the posterior esophagus, the cuticle is absent and the epithelium is ciliated. In this region, epithelial cells may contain larger lipid droplets and glycogen reserves. Subepithelial secretory cells are not present, and in epithelial secretory cells the number of dense vesicles increases, but most secretory cells still contain some electron-lucent vesicles. These cells secrete a mixture of proteins and acid polysaccharides and should be considered seromucous. The secretory cells of the posterior esophagus are significantly different from those previously reported in the anterior esophagus of this herbivorous species.

An ultrastructural study of the activation of the endocrine dorsal bodies in the snail Helix aspersa by mating

1991 ◽  
Vol 69 (5) ◽  
pp. 1203-1215 ◽  
Author(s):  
A. S. M. Saleuddin ◽  
Bernadette Griffond ◽  
Mary-Lou Ashton
Keyword(s):  
Secretory Granules ◽  
Helix Aspersa ◽  
Egg Laying ◽  
Ultrastructural Changes ◽  
Ultrastructural Organization ◽  
Type I ◽  
Golgi Bodies ◽  
Wet Weight ◽  
Snail Helix Aspersa ◽  
The Brain

The ultrastructural organization of the dorsal bodies of Helix aspersa was studied using serial sections. The dorsal body cells, which were found in groups of two to six in the connective tissue surrounding the brain, contacted each other and formed a network. They were innervated by two types of axons. Type I axons conformed with those described in earlier studies as inhibitory and originating from the cerebral green cells. Type II axons contained secretory granules that were morphologically distinct from and smaller than type I granules. Between the dorsal body cells and both axon types, localized modifications of the membrane were evident. Virgin snails, which grew faster (wet weight) than mated snails, did not lay viable eggs. A comparative morphometric analysis of the dorsal bodies of virgin and mated snails showed that in the latter there was an increase in the numbers of mitochondria, secretory granules, and Golgi bodies, with a concomitant decrease in the numbers of lipid droplets. However, no difference was found in the numbers of profiles of exocytotic release of secretory granules with the use of tannic acid methods. Mating, obligatory for oviposition of viable eggs, appeared to cause ultrastructural changes consistent with increased synthesis and release of the dorsal body hormone essential for vitellogenesis, ovulation, and, consequently, egg laying.

scholarly journals LOCALIZATION OF THIAMINE PYROPHOSPHATASE ACTIVITY IN THE GOLGI APPARATUS OF A MOLLUSC, HELIX ASPERSA

1963 ◽  
Vol 18 (1) ◽  
pp. 73-85 ◽  
Author(s):  
G. A. Meek ◽  
S. Bradbury
Keyword(s):  
Electron Microscope ◽  
Golgi Apparatus ◽  
Osmium Tetroxide ◽  
Helix Aspersa ◽  
Multivesicular Bodies ◽  
Animal Cells ◽  
Lead Phosphate ◽  
Thiamine Pyrophosphatase ◽  
Acrosome Formation ◽  
Snail Helix Aspersa

Spermatids of the snail Helix aspersa were studied after fixation in buffered osmium tetroxide and after applying Novikoff and Goldfischer's method (15) for demonstrating thiamine pyrophosphatase (TPPase) activity both with the light and the electron microscope. The appearance of cells in the light microscope after localizing the enzyme is very similar to the appearance after the application of classical Golgi techniques. The electron microscope shows the "dictyosomes" to consist of non-granular membranes, vesicles, and vacuoles typical of the ultrastructure of the Golgi apparatus. Sites of TPPase activity are localized by deposits of lead phosphate, and are found between the membranes of the Golgi apparatus, in the small vesicles, in multivesicular bodies often found associated with it, but not within the large Golgi vacuoles. Heavy deposits are found on the caudal part of the nuclear envelope, but not in the acrosomal granule. It is suggested that TPPase may act as an intermediary in acrosome formation by the Golgi apparatus or "acroblast" of this cell. The finding of diphosphatase activity in the Golgi apparatus of an invertebrate is suggested as additional evidence for the existence of a homology between the Golgi apparatus of all animal cells.

Release of Neurosecretion in the Crayfish Sinus Gland

1968 ◽  
Vol 26 ◽  
pp. 150-151
Author(s):  
Richard R. Shivers
Keyword(s):  
Chemical Nature ◽  
Storage Site ◽  
Neurosecretory Granules ◽  
Sinus Gland ◽  
Diameter Class ◽  
Dense Membrane ◽  
Neurohemal Organ ◽  
Dense Vesicles

The sinus gland is a neurohemal organ located in the crayfish eyestalk and represents a storage site for neurohormones prior to their release into the circulation. The sinus gland contains 3 classes of dense, membrane-limited granules: 1) granules measuring less than 1000 Å in diameter, 2) granules measuring 1100-1400 Å in diameter, and 3) granules measuring 1500-2000 Å in diameter. Class 3 granules are the most electron-dense of the granules found in the sinus gland, while class 2 granules are the most abundant. Generally, all granules appear to undergo similar changes during release.Release of neurosecretory granules may be initiated by a preliminary fragmentation of the “parent granule” into smaller, less dense vesicles which measure about 350 Å in diameter (V, Figs. 1-3). A decrease in density of the granules prior to their fragmentation has been observed and may reflect a change in the chemical nature of the granule contents.

Evaluation of platelet dense granules for determining storage pool deficiencies by HVEM image and quantitative analysis

1996 ◽  
Vol 54 ◽  
pp. 770-771
Author(s):  
W.T. Gunning ◽  
J.N. Turner ◽  
K. Buttle ◽  
E.P. Calomeni ◽  
N.A. Lachant ◽  
...  
Keyword(s):  
Quantitative Analysis ◽  
Platelet Function ◽  
Electron Microscopic ◽  
Von Willebrand's Disease ◽  
Dense Granules ◽  
Storage Pool ◽  
Prolonged Bleeding ◽  
Microscopic Evaluation ◽  
Storage Pools ◽  
Electron Lucent

There are a variety of conditions which have been associated with prolonged bleeding times. If other etiologies including von Willebrand's disease have been ruled out, a platelet function disorder must be considered. The best, if not only, technique to make this diagnosis is the electron microscopic evaluation of whole air dried platelets. Bull first described the presence of dense granules in whole platelets in 1968 and the technique has been utilized extensively The electron dense or delta granules are easily distinguished from the larger more numerous alpha granules which are electron lucent. The significance of the dense granules is that they are known to be “storage pools” of serotonin, calcium, adenosine di- and triphosphate, and pyrophosphate. Prolonged bleeding times may be directly related to an insufficiency of these substances. The diagnosis of a storage pool deficiency is made when either the storage content of the dense granules is abnormal or their number is diminished. We observe normal platelets to have 4-6 dense granules, which agrees with the literature.

Ultrastructure of the female reproductive organs (ovary, vitellaria, and Mehlis' gland) of Halipegus eccentricus (Trematoda: Derogenidae)

1986 ◽  
Vol 64 (10) ◽  
pp. 2203-2212 ◽  
Author(s):  
Jon M. Holy ◽  
Darwin D. Wittrock
Keyword(s):  
Cell Types ◽  
Reproductive Organs ◽  
Golgi Body ◽  
Digenetic Trematode ◽  
Secretory Cells ◽  
Cortical Granules ◽  
Golgi Bodies ◽  
Transmission Electron ◽  
Vitelline Cells ◽  
Female Reproductive Organs

The female reproductive organs (ovary, vitellaria, and Mehlis' gland) of the digenetic trematode Halipegus eccentricus were studied by transmission electron microscopy. Oocytes entered diplotene while in the ovary and produced cortical granules and lipid bodies. Vitelline cells produced large amounts of eggshell protein but no yolk bodies. Two types of Mehlis' gland secretory cells were present, distinguishable by the morphology of their rough endoplasmic reticulum, Golgi bodies, and secretory bodies, and by the persistence of recognizable secretory material within the ootype lumen after exocytosis. In an attempt to standardize the nomenclature regarding the cell types of the Mehlis' gland, a classification that takes into account these four criteria is proposed. Two basic types of Golgi body organization were noted for the cells of the female reproductive system: a stack of flattened cisternae (Mehlis' gland alpha cells) and spherical Golgi bodies with vesicular cisternae (oocytes, vitelline cells, and Mehlis' gland beta cells).

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