Visual objects refine head direction coding

Animals use visual objects to guide navigation-related behaviors, from hunting prey, to escaping predators, to exploring the world. However, little is known about where visual objects are encoded in the mouse brain or how visual objects impact processing within the spatial navigation system. Using functional ultrasound (fUS) imaging in mice, we conducted a brain-wide screen and identified brain areas that were preferentially activated by images of objects compared to scrambled versions of the same stimuli. While visual cortical areas did not show a significant preference, regions associated with spatial navigation were preferentially activated by visual objects. Electrophysiological recordings in the postsubiculum, the primary cortical area of the head direction (HD) system, further confirmed a preference for visual objects, which was present in both HD cells and fast-spiking interneurons. Finally, we found that visual objects dynamically modulate HD cells, selectively increasing firing rates for HD cells aligned with a visual landmark’s direction, while suppressing activity in HD cells coding for other directions. These results reveal that visual objects refine population-level coding of head direction.