scholarly journals Comparative morphology of the rat optic nerve using light and electron microscopy

2010 ◽  
Vol 24 (S1) ◽  
Author(s):  
Joshua Kyle Duncan ◽  
Bryan Anderson ◽  
Jason A. Kaufman ◽  
Andrew Iwaniuk ◽  
T. Bucky Jones ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Optic Nerve ◽  
Light And Electron Microscopy ◽  
Comparative Morphology

Development of the optic nerve in Xenopus laevis

Development ◽  
1982 ◽  
Vol 72 (1) ◽  
pp. 225-249
Author(s):  
Charles Cima ◽  
Philip Grant
Keyword(s):  
Electron Microscopy ◽  
Optic Nerve ◽  
Xenopus Laevis ◽  
Ganglion Cell ◽  
Light And Electron Microscopy ◽  
Near Neighbour ◽  
Dorsoventral Axis ◽  
Fibre Size ◽  
Autoradiographic Analysis ◽  
Young Old

Development of the Xenopus laevis optic nerve was studied by light and electron microscopy from embryonic stage 26, before the retina has formed, to juveniles, 8 months post-metamorphic. Low-power EM photographs of sections through the retinal optic nerve (RON), middle optic nerve (MON) and chiasmatic optic nerve (CON) were prepared at different stages and the areas containing large axons (0·5 μm) were traced in optic nerve reconstructions. Ordering of fibre size along a dorsoventral axis was noted in the embryonic nerve, and this pattern persisted throughout development. Most large fibres, myelinated and unmyelinated, occupy an eccentric dorsocentral position in the MON while small axons are seen in a ventral peripheral crescent. In the CON, the dorsal one third to one half is occupied by large fibres while the ventral CON contains small fibres exclusively. If, as assumed, large axons are older than small axons (0·1–0·3 μm), then patterns of large and small axons along the nerve might reveal a chronotopic fibre ordering. Chronotopic ordering was confirmed by autoradiographic analysis of the distribution of old, labelled fibres and young, unlabelled newly arriving fibres in optic nerves between stage 51 and 57. The young—old labelling pattern corresponds to the small and large axon patterns respectively, in all sections of the optic nerve. Chronotopic ordering of fibres in the developing optic nerve can be explained, in part, by the dorsoventral asymmetric marginal growth of the developing retina and the phenomenon of fibre following as ganglion cell axons join near neighbour fascicles in the retina, converge at the optic disc and grow through the optic nerve.

Fine Structure of the Eye of a Nudibranch Mollusc, Hermissenda Crassicornis

1967 ◽  
Vol 2 (3) ◽  
pp. 349-358
Author(s):  
R. M. EAKIN ◽  
JANE A. WESTFALL ◽  
M. J. DENNIS
Keyword(s):  
Electron Microscopy ◽  
Fine Structure ◽  
Optic Nerve ◽  
Light And Electron Microscopy ◽  
The Other ◽  
Sensory Cells ◽  
Nerve Fibres ◽  
Supporting Cells ◽  
Small Bodies ◽  
Receptor Cells

The eye of a nudibranch, Hermissenda crassicornis, was studied by light and electron microscopy. Three kinds of cells were observed: large sensory cells, each bearing at one end an array of microvilli (rhabdomere) and at the other end an axon which leaves the eye by the optic nerve; large pigmented supporting cells; and small epithelial cells, mostly corneal. There are five sensory cells, and the same number of nerve fibres in the optic nerve. The receptor cells contain an abundance of small vesicles, 600-800 Å in diameter. The lens is a spheroidal mass of osmiophilic, finely granular material. A basal lamina and a capsule of connective tissue enclose the eye. In some animals the eye is ‘infected’ with very small bodies, 4-5 µ in diameter, thought to be symbionts.

Development of the optic nerve in Xenopus laevis

Development ◽  
1982 ◽  
Vol 72 (1) ◽  
pp. 251-267
Author(s):  
Charles Cima ◽  
Philip Grant
Keyword(s):  
Electron Microscopy ◽  
Optic Nerve ◽  
Xenopus Laevis ◽  
Light And Electron Microscopy ◽  
Ependymal Cells ◽  
Glia Limitans ◽  
Nerve Development ◽  
Myelinated Fibres ◽  
Cytoplasmic Processes ◽  
Time Of Origin

We studied the time of origin, development and location of glial elements in the developing optic nerve of Xenopus with light and electron microscopy. The first cells acting as a primitive glia are ependymal cells lying dorsal to the chiasmatic optic nerve (CON) at Nieuwkoop & Faber (1956) NF stage 39. Later (stage 47/48), immature astrocyte cell bodies migrate from the periphery of the middle optic nerve (MON) into the central fibre mass along cytoplasmic processes extending from the outer glia limitans. Shortly thereafter, oligodendrocyte cell bodies appear in the centre of the fibre mass and myelination begins, first in the middle of the MON, spreading from the centre distally towards the chiasm and proximally to the retina. In late tadpoles myelinated fibres appear first in the CON then in the retinal optic nerve (RON) increasing markedly in juveniles and adults. Segment-specific patterns of glia and myelination appear during optic nerve development. During metamorphic climax, the ptic nerve shortens (Cullen & Webster, 1979), a process involving myelin and axon remodelling primarily in the MON. Neither the profound changes during metamorphosis, nor the processes of gliogenesis and myelination significantly alter the underlying chronotopic ordering in the tadpole nerve. In juvenile and adult optic nerves, however, as myelination and gliogenesis increase, and as more axons mature and grow in diameter, the dorsoventral chronotopic arrangement of axons becomes less apparent.

Comparative morphology of zebra (Dreissena polymorpha) and quagga (Dreissena bugensis) mussel sperm: light and electron microscopy

1996 ◽  
Vol 74 (5) ◽  
pp. 809-815 ◽  
Author(s):  
G. K. Walker ◽  
C. A. Edwards ◽  
M. G. Black
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Dreissena Polymorpha ◽  
Osmium Tetroxide ◽  
Light And Electron Microscopy ◽  
Comparative Morphology ◽  
Dreissena Bugensis ◽  
Transmission Electron ◽  
Contrast Microscopy ◽  
Scanning Electron

Adult zebra (Dreissena polymorpha) and quagga (Dreissena bugensis) mussels were induced to release large quantities of live spermatozoa by the administration of 5-hydroxytryptamine (serotonin). Sperm were photographed alive using phase-contrast microscopy and were fixed subsequently with glutaraldehyde followed by osmium tetroxide for eventual examination by transmission or scanning electron microscopy. The sperm of both genera are of the ect-aquasperm type. Their overall dimensions and shape allow for easy discrimination at the light and scanning electron microscopy level. Transmission electron microscopy of the cells reveals a barrel-shaped nucleus in zebra mussel sperm and an elongated nucleus in quagga mussel sperm. In both species, an acrosome is cradled in a nuclear fossa. The ultrastructure of the acrosome and axial body, however, is distinctive for each species. The structures of the midpiece are shown, including a unique mitochondrial "skirt" that includes densely packed parallel cristae and extends in a narrow sheet from the mitochondria.

Haemangioblastoma of the optic nerve. Case report with study by light and electron microscopy

Pathology ◽  
1981 ◽  
Vol 13 (2) ◽  
pp. 357-364 ◽  
Author(s):  
Robert P. Eckstein ◽  
E.J. Wills ◽  
J.N. Segelov
Keyword(s):  
Electron Microscopy ◽  
Case Report ◽  
Optic Nerve ◽  
Light And Electron Microscopy

Fine structure of the pecten oculi of the mallard (Anas platyrhynchos)

1990 ◽  
Vol 68 (3) ◽  
pp. 427-432 ◽  
Author(s):  
Charlie R. Braekevelt
Keyword(s):  
Electron Microscopy ◽  
Fine Structure ◽  
Endothelial Cell ◽  
Optic Nerve ◽  
Blood Vessels ◽  
Anas Platyrhynchos ◽  
Light And Electron Microscopy ◽  
Mallard Duck ◽  
Pecten Oculi ◽  
Region Form

The pecten oculi of the mallard duck (Anas platyrhynchos) has been examined by light and electron microscopy. In this species, the pecten is of the pleated type and 12–14 accordion folds are joined apically by a heavily pigmented bridge of tissue which holds the pecten in a fanlike shape, widest at the base. It is situated over the optic nerve head and extends out into the vitreous. The entire pecten is enclosed by a fine basal lamina and hyalocytes are often present on its outer surface. Within each fold are numerous capillaries, larger blood vessels, and melanocytes. The capillaries are surrounded by thick fibrillar basal laminae which often contain pericytes. These capillaries display extensive microfolds on both the luminal and abluminal borders. The endothelial cell bodies are extremely thin, with most organelles present in a paranuclear location. The melanocytes, which are most plentiful in the bridge region, form an incomplete sheath around the capillaries and other blood vessels. The morphology of the pecten in the mallard is indicative of a heavy involvement in the transport of materials.

scholarly journals Dense HRP filling in pre-fixed brain tissue for light and electron microscopy.

1987 ◽  
Vol 35 (10) ◽  
pp. 1127-1136 ◽  
Author(s):  
G H Kageyama ◽  
R L Meyer
Keyword(s):  
Electron Microscopy ◽  
Optic Nerve ◽  
High Resolution ◽  
Light Microscopy ◽  
Glial Cells ◽  
Light And Electron Microscopy ◽  
Polyethylene Tube ◽  
Fixed Tissue ◽  
Cat Brain

The use of neuroanatomical markers in tissues that have been pre-fixed has been virtually ignored, even though this approach could offer certain advantages over in vivo methods, in terms of convenience of application and choice of markers. We have found that HRP can be used on well-fixed brains of cats and goldfish to fill neurons, dendrites, axons, terminals, glial cells, and glial processes for high-resolution light microscopy and electron microscopy. Best results were obtained using brains that were perfusion-fixed with 2.5% depolymerized paraformaldehyde and 1.5% glutaraldehyde. Two methods of HRP application were used: optically guided injections of microliter quantities into various regions of cat brain, and optic nerve fills in goldfish by attaching an HRP-filled polyethylene tube for periods of 1 day to 2 weeks. HRP applied in these ways to pre-fixed tissue was found to fill neurons or glial cells with solid label in the anterograde and retrograde directions.

The Morphology of Vacuolated Cells in the Liver Following Administration of Vitamin A.

1973 ◽  
Vol 31 ◽  
pp. 408-409
Author(s):  
Odell T. Minick ◽  
Hidejiro Yokoo ◽  
Fawzia Batti
Keyword(s):  
Electron Microscopy ◽  
Body Weight ◽  
Vitamin A ◽  
Light And Electron Microscopy ◽  
Liver Cells ◽  
Prominent Feature ◽  
Vascular Space ◽  
Vacuolated Cell ◽  
Vacuolated Cells ◽  
Vacuolated Cytoplasm

Vacuolated cells in the liver of young rats were studied by light and electron microscopy following the administration of vitamin A (200 units per gram of body weight). Their characteristics were compared with similar cells found in untreated animals.In rats given vitamin A, cells with vacuolated cytoplasm were a prominent feature. These cells were found mostly in a perisinusoidal location, although some appeared to be in between liver cells (Fig. 1). Electron microscopy confirmed their location in Disse's space adjacent to the sinusoid and in recesses between liver cells. Some appeared to be bordering the lumen of the sinusoid, but careful observation usually revealed a tenuous endothelial process separating the vacuolated cell from the vascular space. In appropriate sections, fenestrations in the thin endothelial processes were noted (Fig. 2, arrow).

Control of Autogenous Vein Grafts Prior to Reimplantation, By Electron Microscopy

1972 ◽  
Vol 30 ◽  
pp. 106-107
Author(s):  
John H. L. Watson ◽  
John L. Swedo ◽  
M. Vrandecic
Keyword(s):  
Electron Microscopy ◽  
Light And Electron Microscopy ◽  
Physiological Saline ◽  
Experimental Conditions ◽  
Vein Grafts ◽  
Arterial Blood ◽  
Saphenous Veins ◽  
Autogenous Vein ◽  
Control Of Parameters ◽  
Post Implantation

The ambient temperature and the nature of the storage fluids may well have significant effects upon the post-implantation behavior of venus autografts. A first step in the investigation of such effects is reported here. Experimental conditions have been set which approximate actual operating room procedures. Saphenous veins from dogs have been used as models in the experiments. After removal from the dogs the veins were kept for two hours under four different experimental conditions, viz at either 4°C or 23°C in either physiological saline or whole canine arterial blood. At the end of the two hours they were prepared for light and electron microscopy. Since no obvious changes or damage could be seen in the veins by light microscopy, even with the advantage of tissue specific stains, it was essential that the control of parameters for successful grafts be set by electron microscopy.

Ultrastructure of two neoplasms in culture compared with original biopsies

1984 ◽  
Vol 42 ◽  
pp. 50-51
Author(s):  
Joseph M. Harb ◽  
James T. Casper ◽  
Vlcki Piaskowski
Keyword(s):  
Electron Microscopy ◽  
Tissue Culture ◽  
Biopsy Specimen ◽  
Cultured Cells ◽  
Light And Electron Microscopy ◽  
Human Tumor ◽  
Soft Agar ◽  
Human Tumor Cells ◽  
Morphological Distinction ◽  
Tumor Types

The application of tissue culture and the newer methodologies of direct cloning and colony formation of human tumor cells in soft agar hold promise as valuable modalities for a variety of diagnostic studies, which include morphological distinction between tumor types by electron microscopy (EM). We present here two cases in which cells in culture expressed distinct morphological features not apparent in the original biopsy specimen. Evaluation of the original biopsies by light and electron microscopy indicated both neoplasms to be undifferentiated sarcomas. Colonies of cells propagated in soft agar displayed features of rhabdomyoblasts in one case, and cultured cells of the second biopsy expressed features of Ewing's sarcoma.

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