Inhibitory Control of Feature Selectivity in an Object Motion Sensitive Circuit of the Retina

Publication date: 16 May 2017
Source:Cell Reports, Volume 19, Issue 7
Author(s): Tahnbee Kim, Daniel Kerschensteiner
Object motion sensitive (OMS) W3-retinal ganglion cells (W3-RGCs) in mice respond to local movements in a visual scene but remain silent during self-generated global image motion. The excitatory inputs that drive responses of W3-RGCs to local motion were recently characterized, but which inhibitory neurons suppress W3-RGCs' responses to global motion, how these neurons encode motion information, and how their connections are organized along the excitatory circuit axis remains unknown. Here, we find that a genetically identified amacrine cell (AC) type, TH2-AC, exhibits fast responses to global motion and slow responses to local motion. Optogenetic stimulation shows that TH2-ACs provide strong GABAA receptor-mediated input to W3-RGCs but only weak input to upstream excitatory neurons. Cell-type-specific silencing reveals that temporally coded inhibition from TH2-ACs cancels W3-RGC spike responses to global but not local motion stimuli and, thus, controls the feature selectivity of OMS signals sent to the brain.

Graphical abstract

Teaser

Kim and Kerschensteiner report that a specific amacrine cell type (TH2-AC) distinguishes local and global motion in the kinetics of its responses. Optogenetic activation and cell-type-specific silencing show that TH2-ACs provide strong inhibitory input to object motion sensitive retinal ganglion cells (W3-RGCs) and that this input suppresses W3-RGC responses to global motion stimuli.


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