1982 — 1985 |
Van Sluyters, Richard |
N/AActivity Code Description: No activity code was retrieved: click on the grant title for more information |
Recovery of Binocular Fuction in Visual Cortex @ University of California-Berkeley |
1 |
1985 |
Van Sluyters, Richard C |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Animal Models of Developmental Visual Disorders @ University of California Berkeley
This research seeks to provide experimental animal models of two common human visual disorders. The knowledge gained from these studies will have direct application to the prevention, diagnosis and treatment (including rehabilitation) of people with these developmental disorders. A set of experiments will investigate the effects of visual axis misalignment (strabismus) during development on the cortical physiology of kittens. Single cell and evoked potential recording techniques will be used to examine the time course of the sensitive period for strabismus, the ways kittens adapt successfully to the harmful effects of concomitant strabismus and the potential for recovery from strabismus. Other studies will seek evidence for changes in the visual acuity or visual fields of strabismic kittens. This group of studies will provide a systematic analysis of the full range of cortical deficits caused by strabismus and will increase our understanding of the physiological bases of such clinical anomalies as strabismic amblyopia, anomalous correspondence and decreased stereoacuity. A second series of experiments will examine the role of visual experience in the development of the optokinetic nystagmus (OKN) reflex in the cat. These experiments will assess quantitatively the development of OKN eye movements in normal kittens and in each eye of monocularly deprived kittens. Other studies will examine the role of the visual cortex in mediating OKN in these animals and the extent to which the sensitive periods for disrupting OKN and altering cortical physiology coincide. The data from these studies will bear directly on the physiological mechanisms underlying OKN deficits in humans with amblyopia.
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0.958 |
1985 — 1991 |
Van Sluyters, Richard |
N/AActivity Code Description: No activity code was retrieved: click on the grant title for more information |
Development of Visual Callosal Connections in the Rat @ University of California-Berkeley |
1 |
1986 — 1991 |
Van Sluyters, Richard C |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Development of Central Visual Pathways @ University of California Berkeley
The experiments in this proposal will investigate patterned connections in two central visual pathways in the cat. In each case, our goal is first to confirm current information on the arrangement of these connections in normally reared cats, using a sensitive labeling technique, an alternative method of sectioning the brain, and quantitative analysis of labeling patterns. Preliminary data indicate these studies will also extend previous findings significantly. Then these same techniques will be used to study cats subjected to various forms of visual deprivation, in an effort to establish the roles of genetic and environmental factors in guiding the formation of these connections. The experiments in the first part of this proposal will examine the overall pattern of thalamo-cortical innervation in the visual cortex of normally reared and visually deprived cats. Connections will be revealed by transneuronal transport of a tracer from the eye to areas 17 and 18, and qualitative and quantitative techniques will be used to describe the labeling patterns in tangential sections taken through unfolded and flattened cortical tissue. The results of these experiments will significantly extend earlier findings, and they will complement contemporary data from behavioral, single-unit recording, and single-cell labeling studies. The experiments in the second part of this proposal will examine the overall pattern of visual interhemispheric connections in normally reared, visually deprived, and retinally lesioned cats. Callosal connections of the posterior neocortex will be revealed by antero- and retrograde transport of tracers, and studied in tangential sections. These studies will characterize the overall visual callosal pattern in the cat, describe its relationship to cortical retinotopy, and reveal the roles of retinally based factors and/or patterned activity in guiding its formation.
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0.958 |
1992 — 1995 |
Van Sluyters, Richard C |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Central Visual Pathways @ University of California Berkeley
DESCRIPTION (Investigator's Abstract): The studies outlined in this proposal are designed to investigate the overall arrangement of patterned neural connections in the primary visual area of the cat's cerebral cortex. The awareness that visual cortical areas contain regular modular arrays of neural connections has had a powerful influence on contemporary visual neuroscience. Much of the general appeal of this model of mammalian visual pathways comes from the fact that it is supported by evidence from a variety of species. To the extent that these data can be applied to mammals in general, they are of value in understanding the structure and function of the human visual system. On the other hand, the amount of evidence available from any single non-primate species is actually quite limited. For example, there has been almost none of these kinds of data for the cat, which is one of the more commonly studied animals in visual neuroscience experiments. The experiments of the present proposal are designed to build on the available evidence from the cat and determine the extent to which notions of the modular organization of striate cortex based on data from the monkey can be extended to the cat. The proposed studies will take advantage of the applicants laboratory's experience in revealing and then quantitatively analyzing tangentially arrayed periodic patterns of connections in cat striate cortex. A series of experiments will be conducted in which neuroanatomical labeling and staining techniques are used to visualize features of cortical neural reconstructions of these features and analyze them quantitatively. Data will be collected from both normally reared and visual deprived animals, in an effort to understand the brain mechanisms underlying human visual disorders such as amblyopia. The general significance of this proposal is that this comparative approach is crucial to the success of attempts to uncover common rules of mammalian brain structure and function. The outcome of these experiments will demonstrate whether the cat will continue to be a good model for carrying out further studies on patterned connections in visual cortex. To the extent that such studies are feasible in the cat, they should be encouraged for two reasons. First, they will reveal just how widely any putative general rules of mammalian brain structure and function can be applied. Second, they will indicate whether, in the applicants future efforts to understand the mechanisms underlying normal and abnormal human vision, it will be necessary to abandon the cat and move to the monkey, an animal that is both more costly and more difficult to acquire and maintain than the cat.
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0.958 |