Stimulus-dependent recruitment of lateral inhibition underlies retinal direction selectivity
Abstract
The dendrites of starburst amacrine cells (SACs) in the mammalian retina are preferentially activated by motion in the centrifugal direction, a property that is important for generating direction selectivity in direction selective ganglion cells (DSGCs). A candidate mechanism underlying the centrifugal direction selectivity of SAC dendrites is synaptic inhibition onto SACs. Here we disrupted this inhibition by perturbing distinct sets of GABAergic inputs onto SACs - removing either GABA release or GABA receptors from SACs. We found that lateral inhibition onto Off SACs from non-SAC amacrine cells is required for optimal direction selectivity of the Off pathway. In contrast, lateral inhibition onto On SACs is not necessary for direction selectivity of the On pathway when the moving object is on a homogenous background, but is required when the background is noisy. These results demonstrate that distinct sets of inhibitory mechanisms are recruited to generate direction selectivity under different visual conditions.
Article and author information
Author details
Funding
National Eye Institute
- David Koren
- Wei Wei
Whitehall Foundation
- Wei Wei
E. Matilda Ziegler Foundation for the Blind
- Wei Wei
Karl Kirchgessner Foundation
- Wei Wei
Sloan Foundation
- Wei Wei
The funders provide financial support to this manuscript in study design, data collection and interpretation, and the decision to submit the work for publication.
Ethics
Animal experimentation: All procedures to maintain and use mice were in accordance with the University of Chicago Institutional Animal Care and Use Committee (Protocol number ACUP 72247) and in conformance with the NIH Guide for the Care and Use of Laboratory Animals and the Public Health Service Policy.
Copyright
© 2016, Chen et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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