Direction and orientation preferences in mouse superior colliculus and its retinal inputs exhibit a topography of cardinal biases atop locally mixed tuning

In mouse superior colliculus (SC), neurons are robustly tuned to motion direction and orientation, but it remains controversial whether these preferences form global maps or are arranged in a salt‑and‑pepper fashion, and how this organization relates to that found in the retina and, specifically, the retinal input to the SC.We addressed these questions by combining two‑photon calcium imaging of retinal boutons and SC neurons in superficial SC with Neuropixels recordings across the full depth of SC. We then asked how direction and orientation preferences depend on visual‑field location and how tuning similarity among units depend lateral and vertical distance.Retinal boutons were strongly tuned and closely matched the topographic organization of direction‑ and orientation‑selective ganglion cells, confirming that SC receives a highly ordered, retinocentric code for motion and edges. With increasing depth, SC neurons progressively deviated from this organization. Pairwise and population analyses revealed only weak local clustering, confined to very small spatial scales, and no robust global maps of direction or orientation.These results show that mouse SC inherits a topographic organization of cardinal directions and orientations from the retina and transforms it into a broad coverage of directions and orientations at every visual location, likely supporting readout for diverse visually guided behaviors.