In summary, visual objects refine population-level head-direction coding in postsubiculum, potentially helping the brain’s internal compass anchor to external cues. Whether this extends to other types of spatially tuned neurons remains an exciting open question!
8/
Illustration: Dorothea Laurence

To test if this effect was specific to objects, we presented two landmarks to the mouse: an object picture or a scrambled version. The boost occurred only with the object!
7/

At the population level, head-direction cells form a ring attractor. Cells aligned with an object’s direction were boosted, while others were inhibited—showing that objects refine the brain’s internal compass.⚡🧭 A model confirmed the effect when adding an untuned input to the attractor network.
6/

We then asked: How are visual signals integrated with spatial ones? We teamed up with @apeyrache.bsky.social. Mice were recorded in PoSub while exploring an arena with a landmark, then head-fixed for visual stimulation. Both head-direction cells and fast-spiking interneurons preferred objects!
5/

To our surprise, spatial navigation areas—not visual cortex—responded strongest to objects! We replicated this in awake and anesthetized mice and confirmed it with electrophysiology. Postsubiculum (PoSub), a hub of the head-direction system, was the top hit! 🎯
4/

This project began with a paradox: Mice can see objects, yet no dedicated object areas like those in primates had been found. Inspired by early human fMRI studies, we used an unbiased functional ultrasound (fUS) screen to look beyond the visual cortex.
3/

Thrilled to share that our work is now published in Science! ✨

We found a preference for visual objects in the mouse spatial navigation system where they dynamically refine head-direction coding. In short, objects boost our inner compass! 🧭

www.science.org/doi/10.1126/...

🧵1/

To test if this effect was specific to objects, we presented two landmarks to the mouse: an object picture or a scrambled version. The boost occurred only with the object!
7/

At the population level, head-direction cells form a ring attractor. Cells aligned with an object’s direction were boosted, while others were inhibited—showing that objects refine the brain’s internal compass.⚡🧭 A model confirmed the effect when adding an untuned input to the attractor network.
6/

We then asked: How are visual signals integrated with spatial ones? We teamed up with @apeyrache.bsky.social. Mice were recorded in PoSub while exploring an arena with a landmark, then head-fixed for visual stimulation. Both head-direction cells and fast-spiking interneurons preferred objects!
5/

To our surprise, spatial navigation areas—not visual cortex—responded strongest to objects! We replicated this in awake and anesthetized mice and confirmed it with electrophysiology. Postsubiculum (PoSub), a hub of the head-direction system, was the top hit! 🎯

4/

This project began with a paradox: Mice can see objects, yet no dedicated object areas like those in primates had been found. Inspired by early human fMRI studies, we used an unbiased functional ultrasound (fUS) screen to look beyond the visual cortex.
3/