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Cellular Computation in Primary Visual Cortex

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Date Issued:
2017
Summary:
Individual neurons in the primary visual cortex respond selectively to different features of visual stimuli, such as spatial orientation or direction of motion. A longstanding goal in systems neuroscience has been to understand the transformations single cells perform as they integrate synaptic inputs to generate spiking output. Recent technological developments have facilitated these lines of investigation by enabling direct measurement of the functional properties of single synaptic inputs to neurons in the neocortex. It remains an outstanding question as to whether the tuning of single neocortical neurons can be predicted by their excitatory synaptic inputs. Here, I show that excitatory synaptic inputs exhibit significant functional diversity with respect to orientation and direction selectivity. I show that cells can use at least two strategies to overcome this functional diversity to achieve selective responses in the face of broadly tuned excitatory input: enhancing responses to the preferred stimuli and suppressing responses to the non-preferred stimuli. In the case of orientation selectivity, synaptic inputs cluster according to orientation preference and evoke local dendritic nonlinearities, thereby enhancing somatic responses to the preferred direction. For direction selectivity, cells receive excitatory synaptic inputs tuned to the preferred and null directions, but selectively suppress inputs tuned for the null direction to enhance direction selectivity. This suppression comes from direction-tuned GABAergic interneurons that make longrange, intercolumnar projections to enhance direction selectivity.
Title: Cellular Computation in Primary Visual Cortex.
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Name(s): Wilson, Daniel E., author
Fitzpatrick, David, Thesis advisor
Florida Atlantic University, Degree grantor
Charles E. Schmidt College of Science
Department of Biological Sciences
Type of Resource: text
Genre: Electronic Thesis Or Dissertation
Date Created: 2017
Date Issued: 2017
Publisher: Florida Atlantic University
Place of Publication: Boca Raton, Fla.
Physical Form: application/pdf
Extent: 133 p.
Language(s): English
Summary: Individual neurons in the primary visual cortex respond selectively to different features of visual stimuli, such as spatial orientation or direction of motion. A longstanding goal in systems neuroscience has been to understand the transformations single cells perform as they integrate synaptic inputs to generate spiking output. Recent technological developments have facilitated these lines of investigation by enabling direct measurement of the functional properties of single synaptic inputs to neurons in the neocortex. It remains an outstanding question as to whether the tuning of single neocortical neurons can be predicted by their excitatory synaptic inputs. Here, I show that excitatory synaptic inputs exhibit significant functional diversity with respect to orientation and direction selectivity. I show that cells can use at least two strategies to overcome this functional diversity to achieve selective responses in the face of broadly tuned excitatory input: enhancing responses to the preferred stimuli and suppressing responses to the non-preferred stimuli. In the case of orientation selectivity, synaptic inputs cluster according to orientation preference and evoke local dendritic nonlinearities, thereby enhancing somatic responses to the preferred direction. For direction selectivity, cells receive excitatory synaptic inputs tuned to the preferred and null directions, but selectively suppress inputs tuned for the null direction to enhance direction selectivity. This suppression comes from direction-tuned GABAergic interneurons that make longrange, intercolumnar projections to enhance direction selectivity.
Identifier: FA00004994 (IID)
Degree granted: Dissertation (Ph.D.)--Florida Atlantic University, 2017.
Collection: FAU Electronic Theses and Dissertations Collection
Note(s): Includes bibliography.
Subject(s): Dissertations, Academic -- Florida Atlantic University
Held by: Florida Atlantic University Libraries
Sublocation: Digital Library
Persistent Link to This Record: http://purl.flvc.org/fau/fd/FA00004994
Use and Reproduction: Copyright © is held by the author, with permission granted to Florida Atlantic University to digitize, archive and distribute this item for non-profit research and educational purposes. Any reuse of this item in excess of fair use or other copyright exemptions requires permission of the copyright holder.
Use and Reproduction: http://rightsstatements.org/vocab/InC/1.0/
Host Institution: FAU
Is Part of Series: Florida Atlantic University Digital Library Collections.