Desdemona Fricker

Hi BlueSky — I’m bringing over an old SciTwitter thread series exploring how beautifully the vestibular system works from a systems and computational neuroscience perspective.

Chapter 1 coming shortly! I’ll keep all chapters threaded below.

'The postsubiculum as a head-direction cortex'

by Adrian Duszkiewicz, Desdemona Fricker, Andrea Burgalossi & Adrien Peyrache

@adrian-du.bsky.social @desdemonafricker.bsky.social @apeyrache.bsky.social

www.cell.com/trends/neuro...

New paper alert! 🚨

We found that the brain's compass is remarkably stable at two scales

1️⃣ the system maintains its internal organization for weeks
2️⃣ It "remembers" its orientation for weeks, even after a single visit

This may be key to how the brain aligns its other maps.

Paper: rdcu.be/e3waP

La @semaineducerveau.bsky.social arrive bientôt au SPPIN !

Nous avons le plaisir d’accueillir une conférence suivie d’une visite du laboratoire par @uligraupner.bsky.social dédié aux approches optogénétiques pour comprendre les circuits neuronaux et le comportement.

We had a lot of fun doing these experiments! Theta sweeps in MEC and internal direction signals in parasubiculum track moving objects during pursuit and reverse during backward movement. Simultaneously recorded HD cells in other areas remain locked to head direction across behaviors:

If you are a PhD student or post-doc who wants to learn everything about #electrophysiology or #imaging, consider registering to the Paris Spring school in optical imaging and electrophysiology, that will take place in the center of Paris 11-23 May 2026. Application deadline Feb 2nd
parisneuro.ovh

Active locomotion predictively rescues head direction attractor dynamics in head-fixed mice https://www.biorxiv.org/content/10.64898/2026.01.12.698940v1

Fantastic work!

I’m very happy to share the latest from my lab published in @Nature

Hippocampal neurons that initially encode reward shift their tuning over the course of days to precede or predict reward.

Full text here:
rdcu.be/eY5nh

Plastic landmark anchoring in zebrafish compass neurons Nature - Using two-photon microscopy with a panoramic virtual reality setup, how head direction cells in larval zebrafish integrate visual landmarks and optic flow to track orientation is revealed.

1/6: New publication from the lab: “Plastic landmark anchoring in zebrafish compass neurons” by Ryosuke Tanaka (@ryosuketanaka.bsky.social) and Ruben is available here:
rdcu.be/eX1L4

Projection-specific integration of convergent thalamic and retrosplenial signals in the presubicular head direction cortex Nonlinear dendritic integration in single presubicular neurons provides a mechanism for combining vestibular-based head-direction signals and visual landmark signals to anchor the brain’s internal com...

Coincidence of thalamic HD signal and retrosplenial visual input is detected in the Presubiculum! 🎯 This may be the neuronal basis for landmark anchoring of the HD signal. Pleased to announce the VOR is now available elifesciences.org/articles/92443 Congrats first author Louis Richevaux 🙌

1/n: A new collaborative preprint from the lab to start the year: "A multi-ring shifter network computes head direction in zebrafish" together with Siyuan Mei, Martin Stemmler and Andreas Herz from the LMU, Munich.

Characterizing neuronal population geometry with AI equation discovery The visual cortex contains millions of neurons, whose combined activity forms a population code representing visual stimuli. There is, however, a discrepancy between our understanding of this code at ...

1. New preprint resolving a conundrum in systems neuroscience with an AI scientist, and humans Reilly Tilbury, Dabin Kwon, @haydari.bsky.social, @jacobmratliff.bsky.social, @bio-emergent.bsky.social, @carandinilab.net, @kevinjmiller.bsky.social, @neurokim.bsky.social
www.biorxiv.org/content/10.1...

📢 We are organising the Senses in Motion conference for the third time, and we are now accepting abstracts for posters or talks.

Deadline for abstracts: 19 December
Conference dates: 18–21 May 2026
Location: Harnack House, Berlin

Register via this page👇
sensesinmotion.org

#neuroskyence #neurosky

Grid cells accurately track movement during path integration-based navigation despite switching reference frames - Nature Neuroscience Grid cells do not maintain a stable pattern during a self-motion-based task, but track animal movement in multiple local reference frames and reanchor to task-relevant objects, thus estimating local r...

No GPS in the head? Path integration by entorhinal grid cells without the grid pattern. Interesting paper from Heidelberg. www.nature.com/articles/s41...

Bat Island: The New Era of Science YouTube video by Weizmann Institute of Science

Neuroscience projects last several years, and you are usually a bit jaded by the time you wrap it up. Not this one– spending several months on an island in the middle of nowhere, away from all the craziness of the world reminds you how beautiful the world really is.

www.youtube.com/watch?v=46sv...

The postsubiculum as a head-direction cortex The organisation of thalamocortical networks follows a conserved structure. Traditionally, these are divided into primary sensory systems that receive…

Really excited to share this Opinion piece we've been working on with fellow head-direction cell geeks @apeyrache.bsky.social @desdemonafricker.bsky.social and (bsky-less?) Andrea Burgalossi! While head-direction cells pop up in many cortical regions, we think that one of them is quite unique (1/8)

🚨new paper: the head-direction circuit as a model of primary thalamocortical system. Check this out 👇

kudos to @adrian-du.bsky.social for the huge amount of work put into this opinion piece, starting with the beautiful figures comparing the different thalamocortical systems 🤩

Thanks to the Capitainerie de l’Isle and to Nathalie for hosting our exhibit ✨

Travel awards are available for undergraduate students looking to attend #Cosyne25! The application is short, and the deadline is Nov 12. @cosynemeeting.bsky.social

Application: shorturl.at/6NEyk

More info: www.cosyne.org/travel-grants

(1/2)

Dear #ParisNeuroscience community, here is the schedule of the upcoming 'Neural Networking Night' season !

2/6

Recording in decision-making regions from many neurons at once revealed the neurons' collective evolution as decisions were made

Each decision had two phases: first, neural state was sensitive to sensory inputs; then, trajectories in neural state space turned and became insensitive to inputs.

Thanks to the Capitainerie de l’Isle and to Nathalie for hosting our exhibit ✨

Transitions in dynamical regime and neural mode during perceptual decisions - Nature Simultaneous recordings were made of hundreds of neurons in the rat frontal cortex and striatum, showing that decision commitment involves a rapid, coordinated transition in dynamical regime and neura...

How does the brain decide? 🧠

Our new @nature.com paper shows that neural activity switches from an 'evidence gathering' to a 'commitment' state at a precise moment we call nTc.

After nTc, new evidence is ignored, revealing a neural marker for the instant when the mind is made up.

rdcu.be/eGUrv

Coherent dynamics of thalamic head-direction neurons irrespective of input While the thalamus is known to relay and modulate sensory signals to the cortex, whether it also participates in active computation and intrinsic signal generation remains unresolved. The anterodorsal...

🚨New preprint alert!

The thalamus has long been seen as a relay of sensory signals to cortex.
But could it also generate its own structured activity?
Our study explores this question in the head-direction (HD) system.

Some explanation 🧵👇 1/13

www.biorxiv.org/content/10.1...

Voir Montrer Regarder 👀
Observer Mesurer Vérifier #SciArt
If you are in Paris in September check out our exhibit “Regards Croisés”: Come for the Art, stay for the Science ! This scientific outreach event is supported by @c-brains.bsky.social, @sppin-cnrs.bsky.social and the Capitainerie de l’Isle.

Granularity of thalamic head direction cells Head direction signaling is fundamental for spatial orientation and navigation. The anterodorsal nucleus of the thalamus (ADn) contains a high density of head direction (HD) cells that process sensori...

*New preprint from the lab* – “Granularity of thalamic head direction cells”
doi.org/10.1101/2025...
🧠📈 🧪
1/11

Color-coded mean firing rate maps of place fields detected in the forth trials (left, sorted by the location of place fields peak) and back trials (right, sorted according to firing order in the forth trials) of all bidirectional cells recorded in the track with objects (top) or without objects (bottom). The color represents the intensity of the mean firing rate in a given bin normalized to the maximum mean firing rate (peak rate) in each direction. Note that in the CP condition, the mean firing map in one direction is the mirror image of the mean firing map in the other direction, indicating strong distance coding.

Happy to share our new paper with Mathilde Nordlund and Julie Koenig out @currentbiology.bsky.social. We used virtual reality in mice to study hippocampal distance coding. Our results suggest a primary contribution of grid cells to distance over cue-dependent place cell coding.
shorturl.at/63yFo

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/

Cooperative actions of interneuron families support the hippocampal spatial code Identifying the computational roles of different neuron families is crucial for understanding neural networks. Most neural diversity is embodied in various types of γ-aminobutyric acid–mediated (GABAe...

And the Valero / Buzsaki paper: www.science.org/doi/10.1126/...