PULVINAR INFLUENCES ON GENICULO-CORTICAL ACTIVITY IN THE CAT.
Item
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Title
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PULVINAR INFLUENCES ON GENICULO-CORTICAL ACTIVITY IN THE CAT.
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Identifier
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AAI8203326
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identifier
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8203326
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Creator
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SICA, ANTHONY LOUIS.
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Contributor
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William S. Battersby
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Date
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1981
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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, Physiological
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Abstract
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The effects of pulvinar stimulation on the response in area 17 to a shock in the lateral geniculate nucleus were investigated with both gross and microelectrodes. Data were obtained from twenty-seven male cats prepared for acute study, and maintained on a mixture of N(,2)O and O(,2) during experimentation. The results of gross recording experiments show that activation of either the ipsilateral or contralateral pulvinar increases the amplitude of the cortical response; the magnitude and time course of this response enhancement were similar following stimulation of either pulvinar. These effects were abolished by a functional "blockade" (topical application of KCl) of the medial to posterior-medial suprasylvian gyrus. Extracellular recordings in area 17 show that stimulation of the ipsilateral pulvinar influences the suppression period and afterdischarge of the neuronal response to a geniculate shock. These effects varied as a function of interstimulus interval, i.e., suppression was shortened and the afterdischarge increased at brief intervals, in contrast, suppression is prolonged and the afterdischarge decreased at long intervals. The close similarity of these effects with those found with stimulation of the mesencephalic reticular formation (Alter & Battersby, 1973) suggests that pulvinar and suprasylvian gyrus may form a thalamo-cortical pathway for relaying activity ascending bilaterally from midbrain structures to striate cortex. Extracellular recordings of pulvinar units revealed both functional afferents from the contralateral superior colliculus, and the presence of inhibitory influences descending from the ipsilateral suprasylvian gyrus to the pulvinar. In conclusion, these results suggest that the pulvinar may participate in the extensive changes in cortical activity, e.g., arousal, observed with midbrain stimulation.
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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.
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Program
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Psychology
