Emilie Macé

Exciting times for functional ultrasound! The field is growing fast—and we need to train the next generation. We’re launching the first Paris Ultrasound Workshop, on Dec 8–9 2026. 🎓 Leading experts 🧰 Open-source tools 👩‍🔬 For new & experienced users Register by Nov 15! Link: tinyurl.com/ParisfUSI

1/8. New preprint! ✨ How spontaneous is spontaneous behavior? 🧠🐭 We found that whole-brain fUSi signals predicted spontaneous behavioral transitions seconds in advance. Inhibiting one node of this transition-prone state, the medial septum, facilitated switching! www.biorxiv.org/content/10.6...

7/8. In short: ~10 s before a spontaneous behavioral switch: ↑ decodability ↓ medial septum activity (and other regions) Our interpretation: internal drive gradually builds up, creating a transition-prone brain state that makes switching more likely.

1/8. New preprint! ✨ How spontaneous is spontaneous behavior? 🧠🐭 We found that whole-brain fUSi signals predicted spontaneous behavioral transitions seconds in advance. Inhibiting one node of this transition-prone state, the medial septum, facilitated switching! www.biorxiv.org/content/10.6...

5/8. So what drives this predictability before behavioral transitions? We identified a set of regions whose hemodynamic signal decreased seconds before egress and running, with one potential key player: the medial septum (MS).

1/8. New preprint! ✨ How spontaneous is spontaneous behavior? 🧠🐭 We found that whole-brain fUSi signals predicted spontaneous behavioral transitions seconds in advance. Inhibiting one node of this transition-prone state, the medial septum, facilitated switching! www.biorxiv.org/content/10.6...

3/8 To test this, we used whole-brain fUSi in head-fixed mice across two contexts: a virtual burrow and a running wheel. In both, mice spent most of their time in quiet wakefulness, but spontaneously initiated egress (exiting the burrow), grooming, or running. 🐭

1/8. New preprint! ✨ How spontaneous is spontaneous behavior? 🧠🐭 We found that whole-brain fUSi signals predicted spontaneous behavioral transitions seconds in advance. Inhibiting one node of this transition-prone state, the medial septum, facilitated switching! www.biorxiv.org/content/10.6...

1/8. New preprint! Using fUSi in head-fixed mice🐭, we found that arousal events trigger a brain-wide wave of activity 🌊🧠. Surprisingly, this pattern was preserved during opto manipulations of the locus coeruleus, pointing to a minor role for noradrenergic tone. www.biorxiv.org/content/10.6...

7/8. In sum: arousal engages a brain-wide hemodynamic wave independent of noradrenergic tone! Huge thanks to all the coauthors, institutions, and funders for making this possible! 🙏 @uni-goettingen.de, @mpiforbi.bsky.social, @dfg.de, @ekfstiftung.bsky.social, @mbexc.bsky.social

1/8. New preprint! Using fUSi in head-fixed mice🐭, we found that arousal events trigger a brain-wide wave of activity 🌊🧠. Surprisingly, this pattern was preserved during opto manipulations of the locus coeruleus, pointing to a minor role for noradrenergic tone. www.biorxiv.org/content/10.6...

5/8. This wave propagated from subcortex → cortex. We recovered it from low-dimensional components of resting-state signals. These components predicted both spontaneous and evoked responses in a test set! The arousal wave is a latent state that explains a large fraction of brain-wide signals ⚡

1/8. New preprint! Using fUSi in head-fixed mice🐭, we found that arousal events trigger a brain-wide wave of activity 🌊🧠. Surprisingly, this pattern was preserved during opto manipulations of the locus coeruleus, pointing to a minor role for noradrenergic tone. www.biorxiv.org/content/10.6...

3/8. 🧠👀 Arousal shapes physiology, behavior, perception, and task performance. It also drives brain-wide activity, often more strongly than sensory or task variables. But what is the spatiotemporal structure of this effect? And is it shared between spontaneous and sensory-driven arousal?

1/8. New preprint! Using fUSi in head-fixed mice🐭, we found that arousal events trigger a brain-wide wave of activity 🌊🧠. Surprisingly, this pattern was preserved during opto manipulations of the locus coeruleus, pointing to a minor role for noradrenergic tone. www.biorxiv.org/content/10.6...

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/

Big thanks to our institutions and funding sources for the support—and to everyone on the team for making this discovery possible! 🙏✨ @mbexc.bsky.social @mpiforbi.bsky.social @mcgill.ca @dfg.de

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/

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/

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/

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/

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/