GABAergic amacrine cells balance biased chromatic information in the mouse retina.

The retina extracts chromatic information present in an animal's environment. How this information is processed in the retina is not well understood. In the mouse, chromatic information is not collected equally throughout the retina. Green and UV signals are primarily detected in the dorsal and ventral retina, respectively. However, at the output of the retina, chromatic tuning is more mixed throughout the retina. This suggests that lateral processing by inhibitory amacrine cells shapes chromatic information at the retinal output. We systematically surveyed the chromatic responses of dendritic processes of the 40+ GABAergic amacrine cell types. We identified 25 functional types with distinct chromatic and achromatic properties. We used pharmacology and a biologically inspired deep learning model to explore how inhibition and excitation shape the properties of functional types. Our data suggest that amacrine cells balance the biased spectral tuning of excitation, thereby supporting diversity of chromatic information at the retinal output.