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A A Kosareva

Publications and source records attributed to A A Kosareva.

16 recordsLinked to original sources
PubMed1980

Radioautographic evidence for both orthograde and retrograde axonal transport of labeled compounds after intraocular injection of [3H]proline in the lamprey (Lampetra fluviatilis).

[3H] Proline injected intraocularly in lampreys has been shown to be bidirectionally transported: 24--96 h after the injection, retinofugal fibers and terminals as well as nerve cell bodies at the origin of the retinopetal system were intensely labeled. These results are at variance with the generally held belief that [3H]proline is taken up only by cell bodies and transported by the anterograde flow. The significance of the retrograde axonal transport of [3H]proline in the lamprey retinopetal system is discussed.

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PubMed1980

Retinal projections in lamprey (Lampetra fluviatilis).

Visual projections in lamprey were investigated using two methods,--one by revealing transport of horseradish peroxidase, and the other by silver impregnation of degenerating axons and terminals after enucleation of the eye. Both methods produced similar results. The chiasm showed incomplete crossing of retinal fibres, the major part of which, as an optic tract, proceed along the contralateral thalamus up to the entry into the optic tectum, while the smaller part takes the same course on the ipsilateral side. Besides, from the posterior part of the optic chiasm an axial optic tract branches off, which proceeds through the central part of the contralateral thalamus up to the pretectal nucleus, individual fibres of which enter the central grey layer of the optic tectum. On the contralateral side, the visual projections are localized in the lateral geniculate body, pretectal nucleus, in the three upper layers of the optic tectum, in the ventrolateral area of the optic tectum and as solitary diffuse projections in the mesencephalic tegmentum. Innervation of thalamic and pretectal nuclei are realized by two tracts--the tractus opticus proper, and tractus opticus axialis. On the ipsilateral side visual projections, excepting the optic tract, are scarce and in the thalamus appear as small areas of the lateral geniculate body and pretectum adjacent to the optic tract. Solitary visual projections were found in two upper layers of the rostral optic tectum and in larger numbers in the 3rd and 4th layers of the caudal part and in ventrolateral area of the optic tectum. Projections in mesencephalic tegmentum were single. Diffuse visual projections in the lateral part of hypothalamus could be revealed only by the silver impregnation method. Using the peroxidase method two types of cells were observed in mesencephalic tegmentum where, possibly, the centrifugal fibres proceeding to retina, originate. A comparison is made of central visual projections in lampreys and other representatives of nonmammalian vertebrates.

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PubMed1975

[Corticalization of 2 regions of the visual system in the evolution of vertebrates].

Data on the evolution of the visual system in the phylogenetic scale of vertebrates are reported. Visual projections in the telencephalon of cyclostomes (lampreys) and retinothalamo-telencephalic channel in elasmobranches (skates) are shown. In amphibians (frogs) and reptiles (turtles) the existence of two visual subsystems (retino-thalamo-telencephalic and retino-tecto-thalamo-telencephalic) is determined, both being overlapped partially at the level of n. geniculatus lateralis and totally in the telencephalon. In turtles earlier visual and tectal impulses towards the telencephalon proved to be relayed in n. geniculatus lateralis and later ones--in n. rotundus. In mammals (rats) visual tecto-cortical connections are shown to have one synaptic relay in thalamic structures since cortical potentials evoked by stimulation of the colliculus superior in rats posses a rather short latency. Significant latency shortening of tectal visual responses in monkeys, as compared with the latency of the respective potentials in turtles (chronic identical experiments), supports the idea of the progressive development of the tectal division of the visual system in the vertebrate phylogony. It is concluded that both divisions of the visual system--retino-thalamic and retino-tectal underwent corticalization at earlier evolutionary stages.

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PubMedDate not supplied

[Retinal projections in the lamprey, Lampetra fluviatilis (horseradish perioxidase transport method in the optic nerve)].

After the injection of horseradish peroxidase into the eye of the lamprey L. fluviatilis, the anterograde transport of the enzyme was found in the optic tract itself reaching the optic tectum and via single fibers--the geniculate nucleus. The labeled fibers were also found in the axial optic tract terminating in the geniculate nucleus and in the nucleus of the posterior commissurae. Retrograde transport and labeling of the tracer were observed in cells of the dorsal and central tegmentum.

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PubMedDate not supplied

[Visual projections in to the brain of the sturgeon Acipenser güldenstädti].

Visual projections have been studied after unilateral lesion of the optic nerve. Degenerated fibers and terminals, as well as fibers labelled by horseradish peroxidase were found contralaterally in the lateral geniculate thalamic nucleus, the second (stratum opticum) and the third (stratum fibrosum et griseum superficiale) layers of the midbrain tectum. In other brain structures (lateral ventrothalamic nucleus, in the pretectal area--cortical nucleus, pretectal nucleus, posterior comissure nucleus) the density of degeneration of optic fibers was significantly lower. Separate fragments of degeneration were found in the fourth layer of the tectum. Ipsilaterally, thalamic, pretectal and tectal visual projections of the same localization were found, although they were less massive than at the opposite side.

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PubMedDate not supplied

[Tecto-thalamo-telencephalic interrelationships following visual deafferentation].

21-23 months after uni- and bilateral enucleation of the eyes, the turtles Emys orbicularis and Testudo horsfieldi exhibited atrophy, gliosis and residual degenerative changes in the visual nerves and tracts and in the two upper layers of the optic tectum, as well as a reduced density of fibres in the tecto-thalamic tract on the deafferentated side. Electrophysiological experiments on the turtles have shown that tectal impulses en route to the general cortex of the forebrain are relayed in the n. rotundus. Conduction of impulses along the tecto-geniculo-cortical path, found in intact animals, ceases, which is apparently due to transsynaptic changes in the surface layers of the optic tectum.

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PubMedDate not supplied

[Demonstration of afferent connections of the forebrain in Emys orbicularis turtles by the peroxidase method].

The transport of horseradish peroxidase (HRP) out of the injection site in the dorsal ventricular ridge was studied in turtles Emys orbicularis. Labeled cells in the forebrain were observed in the paleostriatum among fibers of the lateral forebrain bundle. In the thalamus most of cells containing the granular HRP reaction product were located in the n. rotundus, n. reuniens and perirotundal nuclei (n. dorso-medialis anterior, n. magnocellularis thalami, n (centralis) lateralis, n. dorso-medialis). Fewer labeled cells were revealed in the n. anterior and n. ventralis. The density of labeled cells in the majority of all thalamic nuclei increased if the HRP was extended from the dorsal ventricular ridge into the neostriatum and the pallial thickening with adjacent general cortex. HRP positive cells in the pretectal area, nuclei of the posterior commissura and mesencephalic ventro-lateral tegmentum were observed only in cases when the enzyme was diffused from the injection site into the neostriatum, while the HRP retrograde transport to n. geniculatus lateralis, pars dorsalis was revealed only when HRP was extended into the pallial thickening and adjacent general cortex. Ascending connections of the paleostriatum, thalamic nuclei and mesencephalic tegmentum with telencephalic structures, mainly with the dorsal ventricular ridge, were discussed.

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