Understanding modulatory computations in neural pathways of the retina
Abstract/Contents
- Abstract
- The retina performs multiple simultaneous processing operations on the visual scene using a network of only five basic cell types, but more than fifty subtypes. Like many higher order sensory neurons, retinal ganglion cells integrate input through multiple parallel pathways that are influenced by diverse populations of inhibitory interneurons, nearly all of which have unknown function. Understanding the specific contributions of interneuron pathways is difficult because it requires a quantitative model that includes both the interneuron's input, its output, and its effects on other sensory inputs. Here we present an experimental and computational approach to discover all of these relationships together. We studied the visual computations performed by amacrine cells, a class of inhibitory interneuron. Like inhibitory interneurons in other neural circuits, amacrine cells are highly diverse in their physiology and occupy distinct anatomical layers. To measure how the signals transmitted through individual sustained amacrine cells contribute to retinal output, we presented white noise visual stimuli to the intact, isolated salamander retina. We recorded intracellularly from and injected current into single amacrine cells while recording spiking activity from the ganglion cell population of the salamander retina using a multielectrode array. In this way, many simultaneous paired recordings were performed. To characterize the contribution of the amacrine cell, we first characterized the amacrine cell preferred stimulus feature. Then using the method of Spike-Triggered Covariance (STC), we measured the response of ganglion cells to the subspace of stimuli that was different from the amacrine preferred feature. Using this method, we were able to characterize both modulatory and additive effects of the amacrine pathway on other features encoded by the ganglion cell. We found great diversity in functional effects of amacrine cells, consisting of the linear effect in which amacrine pathway contributes in building the receptive field of the ganglion cell, and nonlinear effects in which amacrine pathway modulates the ganglion cell's response function for other visual features. Our analysis indicates that the amacrine cell population defines a context that modulates the multiple features conveyed by the ganglion cell. Because modulation occurs throughout the nervous system, our approach provides a general strategy to understand the functional contributions of specific neurons to computations in a complex circuit.
Description
| Type of resource | text |
|---|---|
| Form | electronic; electronic resource; remote |
| Extent | 1 online resource. |
| Publication date | 2013 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Associated with | Nategh, Neda |
|---|---|
| Associated with | Stanford University, Department of Electrical Engineering. |
| Primary advisor | Baccus, Stephen A |
| Thesis advisor | Baccus, Stephen A |
| Thesis advisor | Boahen, Kwabena (Kwabena Adu) |
| Thesis advisor | Ganguli, Surya, 1977- |
| Thesis advisor | Shenoy, Krishna V. (Krishna Vaughn) |
| Advisor | Boahen, Kwabena (Kwabena Adu) |
| Advisor | Ganguli, Surya, 1977- |
| Advisor | Shenoy, Krishna V. (Krishna Vaughn) |
Subjects
| Genre | Theses |
|---|
Bibliographic information
| Statement of responsibility | Neda Nategh. |
|---|---|
| Note | Submitted to the Department of Electrical Engineering. |
| Thesis | Thesis (Ph.D.)--Stanford University, 2013. |
| Location | electronic resource |
Access conditions
- Copyright
- © 2013 by Neda Nategh
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