Visual objects refine head direction coding

Animals use visual objects to guide navigation-related behaviors, from
hunting prey to escaping predators and exploring the world. However,
little is known about where visual objects are encoded in the mouse brain
or how they impact processing in the spatial navigation system. Using
functional ultrasound imaging, we conducted a brain-wide screen and
identified areas preferentially activated by images of objects compared to
scrambled versions. While visual cortical areas did not show a significant
preference, brain areas 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, confirmed a preference for visual objects in both
HD cells and fast-spiking interneurons. Finally, we found that visual
objects dynamically modulated HD cells in freely moving animals,
selectively increasing firing rates of HD cells aligned with a visual
object while decreasing activity in HD cells coding for other directions.