Sensorimotor development in the neonatal whisker system.
Item
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Title
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Sensorimotor development in the neonatal whisker system.
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Identifier
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AAI3169949
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identifier
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3169949
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Creator
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Landers, Margo S.
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Contributor
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Adviser: H. Philip Zeigler
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Date
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2005
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Language
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English
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Publisher
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City University of New York.
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Subject
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Psychology, Psychobiology
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Abstract
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Studies of sensorimotor systems have suggested that associations between body movements and their sensory consequences during development may make an important contribution to the functional organization of the system. The whisker system is a widely used model for central pattern generation, neural behavioral development and sensorimotor integration and neural pathways have been well established. However, there is little information on the development of behavior in this system and the influence of early sensory inputs. The Introduction to this dissertation describes data that explore the utility of methods that reduce whisking-generated afference during development (Landers, Pytte and Zeigler, 2002). Chapter 2 examines the normal development of whisking and the contribution of sensory inputs to the initial emergence and subsequent refinement of the whisking pattern. Treatments producing varying degrees of postnatal whisker deafferentation were used and whisking across the first month of life was measured using video analysis. Results confirmed a previous report by Welker (1964) that whisking emerges during the second postnatal week, and preceding eye opening by two days. In contrast to the absence of effects in adults, whisker deafferentation in pups delayed the emergence of whisking. Effects on whisking emergence were determined by the amount, source and timing of the reduction in vibrissa sensory inputs. Selectively blocking motor-generated afference potentiated the effect of deafferentation. An implication is that whisker deafferentation during development may delay the emergence of whisking by reducing neural activity modulating central pattern generation (CPGs).;In addition to studies on the development of whisking, this Dissertation examines the development of whisker morphology. Results showed that the most pronounced whisker growth occurs during the first month of life. Early sensory and motor deafferentation resulted in significantly smaller whiskers.;To provide a comprehensive understanding of effects of experiential factors on whisking development and whisker size, Chapter 3 proposes an enrichment model. Binocular neonatal enucleations at P3 resulted in increased size of the whiskers and whisking frequencies. This suggests that early visual deprivation enhances the whisker system in rats. The neural mechanisms underlying the effects of sensory inputs on whisking development and behavioral development have yet to be explored.
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Type
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dissertation
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Source
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PQT Legacy CUNY.xlsx
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degree
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Ph.D.
