Fine structure of the photoreceptor cells of the ground squirrel (Citellus tridecemlineatus tridecemlineatus)

1966 ◽  
Vol 118 (2) ◽  
pp. 359-373 ◽  
Author(s):  
Martin J. Hollenberg ◽  
Maurice H. Bernstein
Keyword(s):  
Fine Structure ◽  
Ground Squirrel ◽  
Photoreceptor Cells

The fine structure of the adrenal cortex of the 13-lined ground squirrel

1968 ◽  
Vol 123 (2) ◽  
pp. 297-313 ◽  
Author(s):  
William G. Seliger ◽  
Wayne F. Smith
Keyword(s):  
Fine Structure ◽  
Adrenal Cortex ◽  
Ground Squirrel

Sequence of Changes in the Fine Structure of the Retina of Dogs Irradiated During Retinal Maturation

1967 ◽  
Vol 25 ◽  
pp. 166-167
Author(s):  
James N. Shively ◽  
Robert D. Phemister ◽  
Glenwood P. Epling
Keyword(s):  
Fine Structure ◽  
Ionizing Radiation ◽  
Photoreceptor Cells ◽  
Rosette Formation ◽  
Severe Dysplasia ◽  
Outer Segments ◽  
Mammalian Retina ◽  
Retinal Dysplasia

It has been known since early in this century that exposure to ionizing radiation during maturation of the mammalian retina results in necrosis of post-mitotic differentiating cells in the nuclear layer, followed by marked retinal dysplasia with rosette formation, and partial to complete agenesis of outer segments of photoreceptor cells. The effect has been morphologically related to the area of the retina undergoing differentiation at the time of irradiation. Alteration in spacial and pressure relationships are said to result in the tubular rosette formations. These effects have been described in mice, rats, monkeys, dogs and man. Doses less than 25 R have produced severe dysplasia in the developing retina of mice. The mature retina is damaged only by doses of several hundred to a few thousand R.

Fine structure of photoreceptor cells in the earthworm, Lumbricus terrestris

1970 ◽  
Vol 104 (3) ◽  
pp. 345-357 ◽  
Author(s):  
P. R�hlich ◽  
B. Aros ◽  
Sz. Vir�gh
Keyword(s):  
Fine Structure ◽  
Lumbricus Terrestris ◽  
Photoreceptor Cells ◽  
Earthworm Lumbricus

Pineal Photoreceptor Cells in Culture: Fine Structure, and Light/ Dark Control of Cyclic Nucleotide Levels and Melatonin Secretion

1992 ◽  
Vol 4 (5) ◽  
pp. 641-651 ◽  
Author(s):  
Jack Falcoón ◽  
Valérie Bégay ◽  
Colette Besse ◽  
Jean-Paul Ravault ◽  
Jean-Pierre Collin
Keyword(s):  
Fine Structure ◽  
Cyclic Nucleotide ◽  
Photoreceptor Cells ◽  
Melatonin Secretion ◽  
Dark Control ◽  
Cells In Culture

Experimental retinal detachment in the cone-dominant ground squirrel retina: Morphology and basic immunocytochemistry

2002 ◽  
Vol 19 (5) ◽  
pp. 603-619 ◽  
Author(s):  
KENNETH A. LINBERG ◽  
TSUTOMU SAKAI ◽  
GEOFFREY P. LEWIS ◽  
STEVEN K. FISHER
Keyword(s):  
Retinal Detachment ◽  
Ground Squirrel ◽  
Outer Nuclear Layer ◽  
Photoreceptor Cells ◽  
Ground Squirrels ◽  
Subretinal Space ◽  
Proliferating Cells ◽  
Significant Difference ◽  
Cone Opsins ◽  
Calbindin D

The cellular responses of the cone-dominant ground squirrel retina to retinal detachment were examined and compared to those in rod-dominant species. Retinal detachments were made in California ground squirrels. The retinas were prepared for light, electron, and confocal microscopy. Tissue sections were labeled with antibodies to cone opsins, rod opsin, glial fibrillary acidic protein (GFAP), vimentin, synaptophysin, cytochrome oxidase, and calbindin D 28K. Wax sections were probed with the MIB-1 antibody to detect proliferating cells. By 10 h postdetachment many photoreceptor cells in the ground squirrel already show structural signs of apoptosis. At 1 day many photoreceptors have collapsed inner segments (IS), yet others still have short stacks of outer segment discs. At 3 days there is a marked increase in the number of dying photoreceptors. Rod and medium-/long-wavelength opsins are redistributed in the cell membrane to their synaptic terminals. At 7 days photoreceptor cell death has slowed. Some regions of the outer nuclear layer (ONL) have few photoreceptor somata. IS remnants are rare on surviving photoreceptors. At 28 days these trends are even more dramatic. Retinal pigmented epithelium (RPE) cells do not expand into the subretinal space. The outer limiting membrane (OLM) appears flat and uninterrupted. Müller cells remain remarkably unreactive; they show essentially no proliferation, only negligible hypertrophy, and there is no increase in their expression of GFAP or vimentin. Horizontal cells show no dendritic sprouting in response to detachment. The speed and extent of photoreceptor degeneration in response to detachment is greater in ground squirrel than in cat retina—only a small number of rods and cones survive at 28 days of detachment. Moreover, the almost total lack of Müller cell and RPE reactivity in the ground squirrel retina is a significant difference from results in other species.

Fine Structure of Platelet Interaction with a New Microcrystalline Collagen Preparation

1974 ◽  
Vol 32 ◽  
pp. 58-59
Author(s):  
W. H. Zucker ◽  
R. G. Mason
Keyword(s):  
Fine Structure ◽  
Platelet Aggregation ◽  
Hydrochloric Acid ◽  
Whole Blood ◽  
Platelet Adhesion ◽  
Hemostatic Agent ◽  
Native Collagen ◽  
Fibrillar Morphology ◽  
Clinical Interest ◽  
New Form

Platelet adhesion initiates platelet aggregation and is an important component of the hemostatic process. Since the development of a new form of collagen as a topical hemostatic agent is of both basic and clinical interest, an ultrastructural and hematologic study of the interaction of platelets with the microcrystalline collagen preparation was undertaken.In this study, whole blood anticoagulated with EDTA was used in order to inhibit aggregation and permit study of platelet adhesion to collagen as an isolated event. The microcrystalline collagen was prepared from bovine dermal corium; milling was with sharp blades. The preparation consists of partial hydrochloric acid amine collagen salts and retains much of the fibrillar morphology of native collagen.

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