Fine Structure of the Retino-Optic Nerve Junction in Dogs

Miyake, Eiji; Imagawa, Tomohiro; Uehara, Masato

doi:10.1292/jvms.66.1549

Cited by 5 publications

(6 citation statements)

References 19 publications

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“…However, the lower (ventral) bundle in the figure has exclusively unmyelinated fibers. These findings are similar to findings from studies in amphibians, mammals, and other fish which show the occurrence of myelinated and unmyelinated processes in the optic nerve (Cima and Grant, 1982; Easter et al, 1984; Collin et al, 2000; Miyake et al, 2004). In the developing frog ( Xenopus laevis ), large myelinated and unmyelinated axons in the optic nerve tend to be found in the dorsocentral optic nerve, while small axons occupy a ventral peripheral position (Cima and Grant, 1982).…”

Section: Discussionsupporting

confidence: 89%

The Effects of Rearing Light Level and Duration Differences on the Optic Nerve, Brain, and Associated Structures in Developing Zebrafish Larvae: A Light and Transmission Electron Microscope Study

Chapman

Tarboush

Connaughton

2012

The Anatomical Record

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The ultrastructure of the optic nerve, brain, and some associated structures of larval zebrafish, grown under three different light regimens were studied. Fish grown under cyclic light (control), constant dark (CD), and constant light (CL) were studied for 4 and 8 days postfertilization (dpf). We also studied the control and CD fish at 15 dpf. The brains of the control and CL fish were larger at 4 dpf than at 8 dpf. In all 4 dpf fish, the brain occupied the entire expanse between the two retinas and the optic nerve extended the shortest distance between the retina and the brain. The 15 dpf zebrafish had the smallest brain size. Groups of skeletal muscle cells associated with the optic nerves became visible in all older larvae. In the 15 dpf larvae, bulges and dilations in the optic nerve occurred as it reached the brain and optic chiasms occurred proximal to the brain. Electron microscopy yielded information about myelinated and unmyelinated axons in the optic nerve, the dimensions of neurotubules, neurofilaments, and myofilaments, including a unique variation in actin myofilaments, and a confirmation of reported myosin myofilament changes (but with dimensions). We also describe the ultrastructure of a sheath-like structure that is confluent over the optic nerve and the brain, which has not been described before in zebrafish. Also presented are images of associated fibroblasts, epithelial cells lining the mouth, cartilage plates, blood vessels, nerve bundles, and skeletal muscle cells, most of which have not been previously described in the literature. Anat Rec, 295:515-531,

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Section: Discussionsupporting

confidence: 89%

The Effects of Rearing Light Level and Duration Differences on the Optic Nerve, Brain, and Associated Structures in Developing Zebrafish Larvae: A Light and Transmission Electron Microscope Study

Chapman

Tarboush

Connaughton

2012

The Anatomical Record

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“…In goats, our study revealed that the intraocular nerve fibers, which represented the scleral, the chroidal and the retinal parts, were totally unmyelinated as it was in canine (Shively et al, 1970); camels (Derbalah, 2001) and bovine (Aly, 2003). On the contrary, Miyake et al, (2004) in dogs reported that the scleral and the chroidal sections consisted largely of myelinated fibers. The failure of myelination in the intraocular fibers seemed to be due to prevention of oligodendrocytes progenitor cells (oligodendroblasts) to migrate from the extraocular into the intraocular sites (Frenchconstant, 1988;Perry and Lund, 1990).…”

Section: Discussionmentioning

confidence: 93%

“…The failure of myelination in the intraocular fibers seemed to be due to prevention of oligodendrocytes progenitor cells (oligodendroblasts) to migrate from the extraocular into the intraocular sites (Frenchconstant, 1988;Perry and Lund, 1990). Miyake et al, (2004) Supposed that the less myelination of the axons of the retinal nerve fiber layer was due to the more transparency of the retina. In sub -mammals, the retina contains oligodendrocyte and myelinated fibers but was not opaque.…”

Section: Discussionmentioning

confidence: 99%

“…The point of transition from the photosensitive portion to the non photosensitive portion is called ora ciliaris retinae in domestic animals and ora serrata in human (Banks, 1993). In the available literature, it has been found that the structure of the eyeball studied in many species of animals including some laboratory animals as Geunia pigs (Spira -Milman, 1979), rats (Smell et al, 1987), ferrets (Braekevelt, 1982), mouse (Carter-Dawson and lavil, 1979) and rabbits (Mills and Massey, 1992); pet animal as dogs (Miyake et al, 2004) and cats (Braekevelt, 1990) and domestic animals as horse (Altuny, 2000), camels (Derbalah, 2001), cattle (Altuny, 2004), buffaloes (Kassab and Sugita, 2001), sheep (Nilsson et al, 1973 a,b). The goats received a little attention of the researchers.…”

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confidence: 99%

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Light and electron microscopic structure of goat's retina

Soliman¹,

Adam

allah

2010

Journal of Veterinary Medical Research

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The present study was conducting aiming to throw the light on the retinal structure on the level of both light and electron microscope. Eyeballs of 35 adult clinically healthy goats of both sexes were collected from Beni-Suef abattoir. The eyeballs were clinically examined before they were dissected and fixed in 10% buffed neutral formalin and in Bouin's solution for 24 hours. The specimens were then processed for light and transmission electron microscope. The retina (pars optica retinae) of the goats extends rostrally to cover the ciliary body as pars ciliaris retinae and the iris as the pars iridis retinae. Pars optica retinae and pars iridis retinae form the light non sensitive parts of the retina, while the sensitive part except at the transition zone; the ora serrata and the optic disc, appeared to be formed of ten layers, named from outward to inward as, retinal pigmented epithelium, rods and cones layer (photoreceptor cell layer), external limiting membrane, outer nuclear layer (cell bodies and nuclei of the photoreceptor cells), outer plexiform layer, inner nuclear layer (contained the horizontal, bipolar, Muller and amacrine cells), inner plexiform layer, ganglionic cell layer, nerve fiber cell layer (unmyelinated nerve fibers) and internal limiting membrane.

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“…This can be imaginied as an additional amplification of the available light next to its twofold use. Dogs' tapetum contain zinc cystein, but riboflavin has not been reported, making it uncertain with other animals (Miyake, Imagawa, & Uehara, 2004). In humans, centrifugal and centripetal axons are responsible for bottom-up and top-down responses, respectively (Evans & De Lahunta, 2013), but in dogs the existence of such axons needs confirmation.…”

Section: Tapetum Lucidummentioning

confidence: 99%

Functional performance of the visual system in dogs and humans: A comparative perspective

Barber¹,

Mills²,

Montealegre-Z³

et al. 2020

CCBR

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Vision in dogs is generally considered poor compared with humans, and recent reports have reviewed some of the physiological principles underpinning dog vision, but a systematic comparison of the physiological and neurobiological features of vision in dogs compared with humans appears to be lacking. This means there is a risk of an anthropocentric perspective of the topic rather than an understanding grounded in a wider biological context. It is also important to appreciate that deficits in one aspect may be compensated for in other parts of the visual system, so generalizing about performance on the basis of a single feature within the visual system might be misleading. This review provides an overview of the visual perceptual abilities of dogs versus humans, grounded in the visual system's physical structures (see supplementary information) for detecting different visual features of the environment through to its initial processing prior to its cognitive evaluation. Differences and variations that exist between dogs and humans and why these might occur are considered, by reference to their natural history (ecological factors affecting their evolution) and differences in morphology (including differences in height, which will affect viewpoint and the visual information available to individuals in the same location). The implications of differences and applications for everyday handling and training of the dogs are discussed throughout.

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Fine Structure of the Retino-Optic Nerve Junction in Dogs

Cited by 5 publications

References 19 publications

The Effects of Rearing Light Level and Duration Differences on the Optic Nerve, Brain, and Associated Structures in Developing Zebrafish Larvae: A Light and Transmission Electron Microscope Study

The Effects of Rearing Light Level and Duration Differences on the Optic Nerve, Brain, and Associated Structures in Developing Zebrafish Larvae: A Light and Transmission Electron Microscope Study

Light and electron microscopic structure of goat's retina

Functional performance of the visual system in dogs and humans: A comparative perspective

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