Page 1 |
Save page Remove page | Previous | 1 of 97 | Next |
|
small (250x250 max)
medium (500x500 max)
large ( > 500x500)
Full Resolution
All (PDF)
|
This page
All
Subset |
DEPENDENCE OF RABBIT RETINAL SYNCHRONY ON VISUAL STIMULATION
PARAMETERS
by
Susmita Chatterjee
A Dissertation Presented to the
FACULTY OF THE GRADUATE SCHOOL
UNIVERSITY OF SOUTHERN CALIFORNIA
In Partial Fulfillment of the
Requirements for the Degree
DOCTOR OF PHILOSOPHY
(BIOMEDICAL ENGINEERING)
August 2008
Copyright 2008 Susmita Chatterjee
Object Description
| Title | Dependence of rabbit retinal synchrony on visual stimulation parameters |
| Author | Chatterjee, Susmita |
| Author email | susmitac@usc.edu |
| Degree | Doctor of Philosophy |
| Document type | Dissertation |
| Degree program | Biomedical Engineering |
| School | Viterbi School of Engineering |
| Date defended/completed | 2008-05-12 |
| Date submitted | 2008 |
| Restricted until | Unrestricted |
| Date published | 2008-07-02 |
| Advisor (committee chair) | Grzywacz, Norberto M. |
| Advisor (committee member) |
Mel, Bartlett Weiland, James Hirsch, Judith D'Argenio, David Merwine, David |
| Abstract | Neighboring retinal ganglion cells often spike synchronously, but the possible function and mechanism of this synchrony is unclear. Recently, the strength of the fast correlation between On-Off directionally selective cells of the rabbit retina was shown to be stimulus dependent. Here, we extend that study, investigating stimulus-dependent correlation among multiple ganglion-cell classes, using multi-electrode recordings. The work towards this dissertation generalized those for directionally selective cells. All cell pairs exhibiting significant spike synchrony did it for an extended edge but rarely for full-field stimuli. The strength of this synchrony did not depend on the amplitude of the response and correlations could be present even when the cells' receptive fields did not overlap. We found that motion is not necessary for synchrony, i.e., it can occur with static flashes of bars. In addition, correlations tended to be orientation selective in a manner predictable by the relative positions of the receptive fields. Interestingly, extended edges and full-field stimuli produced significantly greater and smaller correlations than predicted by chance respectively. We observed synchrony for edges at contrasts as low as 10% making them viable for natural image contrast statistics. We propose an amacrine-network model for the enhancement and depression of correlation. We find that with reasonable biophysical assumptions, the simulation of the network model will exhibit stimulus-appropriate facilitation and suppression of synchrony. The model further provides verifiable predictions for the rate of fast synchrony for discontinuous edges. We have supported the predictions of the model with experimental data and found fast ms-synchrony to disappear for discontinuous edge. Such an apparently purposeful control of correlation adds evidence for retinal synchrony playing a functional role in vision. |
| Keyword | rabbit-retina; ganglion cells; synchrony; stimulus-dependent; amacrine-cell network |
| Language | English |
| Part of collection | University of Southern California dissertations and theses |
| Publisher (of the original version) | University of Southern California |
| Place of publication (of the original version) | Los Angeles, California |
| Publisher (of the digital version) | University of Southern California. Libraries |
| Type | texts |
| Legacy record ID | usctheses-m1313 |
| Rights | Chatterjee, Susmita |
| Repository name | Libraries, University of Southern California |
| Repository address | Los Angeles, California |
| Repository email | http://www.usc.edu/isd/libraries/services/ask_a_librarian/email/ |
| Filename | etd-Chatterjee-20080702 |
| Archival file | uscthesesreloadpub_Volume26/etd-Chatterjee-20080702.pdf |
Description
| Title | Page 1 |
| Full text | DEPENDENCE OF RABBIT RETINAL SYNCHRONY ON VISUAL STIMULATION PARAMETERS by Susmita Chatterjee A Dissertation Presented to the FACULTY OF THE GRADUATE SCHOOL UNIVERSITY OF SOUTHERN CALIFORNIA In Partial Fulfillment of the Requirements for the Degree DOCTOR OF PHILOSOPHY (BIOMEDICAL ENGINEERING) August 2008 Copyright 2008 Susmita Chatterjee |
Comments
Post a Comment for Page 1
