Thomas Euler

Visual processing starts in the retina, where at least 40 distinct features are extracted and sent through parallel channels to higher visual centers in the brain. One of the biggest remaining challenges in retinal research is to understand how these diverse representations arise within the retinal circuits. The origin of this vast functional diversity lies in the retina’s second synaptic layer, the inner plexiform layer, where bipolar cells, amacrine cells and ganglion cells form complex interconnected networks. In particular the amacrine cells are crucial for decorrelating different functional channels: They tune the ganglion cells’ responses, which represent the retina’s output, by modulating glutamate release from bipolar cells as well as heavily shaping the signal integration in the ganglion cell dendritic arbors. Still surprisingly little is known about the great majority of the 60+ genetic types of amacrine cells and their intricate networks in the inner retina. In this project, we aim to dissect the functional roles of different amacrine cell circuits for image processing. To this end, we will combine functional 2-photon imaging of excitatory and inhibitory signals in the mouse retina with computational modeling based on connectomics data from electron microscopy.