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bioRxiv · 10.1101/831453

Antagonistic center-surround mechanisms for direction selectivity in the retina

Ankri, L.·Ezra-Tsur, E.·Maimon, S. R.·Kaushansky, N.·Rivlin-Etzion, M.
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Abstract

A key feature in sensory processing is center-surround receptive field antagonism. Retinal direction-selectivity (DS) relies on asymmetric inhibition from starburst amacrine cells (SAC) to direction selective ganglion cells (DSGC). SAC exhibit antagonistic center-surround, depolarizing to light increments and decrements in their center and surround, respectively, but the role of this property in DS remains elusive. We found that a repetitive stimulation exhausts SAC center and enhances its surround and used it to distinguish center-from surround-mediated responses. Center, but not surround stimulation, induced direction-selective responses in SAC, as predicted by an elementary spatiotemporal model. Nevertheless, both SAC center and surround elicited direction-selective responses in DSGCs, but to opposite directions. Physiological and morphology-based modeling data show that the opposed responses resulted from inverted DSGCs excitatory-inhibitory temporal balance, indicating that SAC response time rules DS. Our findings reveal antagonistic center-surround mechanisms for DS, and demonstrate how context-dependent center-surround reorganization enables flexible computations.

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Ankri, L., Ezra-Tsur, E., Maimon, S. R., Kaushansky, N., Rivlin-Etzion, M.. 2019-11-05. Antagonistic center-surround mechanisms for direction selectivity in the retina. https://doi.org/10.1101/831453

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