Bidirectional encoding of motion contrast in the mouse superior colliculus
Abstract
Detection of salient objects in the visual scene is a vital aspect of an animal's interactions with its environment. Here, we show that neurons in the mouse superior colliculus (SC) encode visual saliency by detecting motion contrast between stimulus center and surround. Excitatory neurons in the most superficial lamina of the SC are contextually modulated, monotonically increasing their response from suppression by the same-direction surround to maximal potentiation by an oppositely-moving surround. The degree of this potentiation declines with depth in the SC. Inhibitory neurons are suppressed by any surround at all depths. These response modulations in both neuronal populations are much more prominent to direction contrast than to phase, temporal frequency, or static orientation contrast, suggesting feature-specific saliency encoding in the mouse SC. Together, our findings provide evidence supporting locally generated feature representations in the SC, and lay the foundations towards a mechanistic and evolutionary understanding of their emergence.
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Source data files have been provided for Figures 1-7.
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Author details
Funding
National Institutes of Health (R01EY020950)
- Jianhua Cang
National Institutes of Health (R01EY026286)
- Jianhua Cang
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Ethics
Animal experimentation: All experimental procedures were approved by the Northwestern University Institutional Animal Care and Use Committee, protocol #IS00001946.
Reviewing Editor
- Fred Rieke, University of Washington, United States
Publication history
- Received: January 20, 2018
- Accepted: July 1, 2018
- Accepted Manuscript published: July 2, 2018 (version 1)
- Version of Record published: July 17, 2018 (version 2)
Copyright
© 2018, Barchini 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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