Desdemona Fricker
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desdemonafricker.bsky.social
Desdemona Fricker
@desdemonafricker.bsky.social
Neuroscientist and Research Director @CNRS. «Orientation&Coordination» team. Head direction, interneurons, memory. Saints-Pères, Paris 👩‍🔬🧠
Reposted by Desdemona Fricker
No GPS in the head? Path integration by entorhinal grid cells without the grid pattern. Interesting paper from Heidelberg. www.nature.com/articles/s41...
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...
www.nature.com
October 30, 2025 at 4:03 PM
Reposted by Desdemona Fricker
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...
Bat Island: The New Era of Science
YouTube video by Weizmann Institute of Science
www.youtube.com
October 17, 2025 at 7:07 AM
Reposted by Desdemona Fricker
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)
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…
www.sciencedirect.com
October 15, 2025 at 8:10 PM
Reposted by Desdemona Fricker
🚨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 🤩
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)
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…
www.sciencedirect.com
October 15, 2025 at 9:39 PM
Reposted by Desdemona Fricker
Thanks to the Capitainerie de l’Isle and to Nathalie for hosting our exhibit ✨
September 28, 2025 at 10:08 PM
Reposted by Desdemona Fricker
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)
Travel Grants — COSYNE
Apply for COSYNE 2026 Travel Grants to support your participation in Lisbon and Cascais, Portugal. Grants are available for students, postdocs, and PIs, including programs for Childcare, Presenters, N...
www.cosyne.org
October 3, 2025 at 3:10 PM
Reposted by Desdemona Fricker
Dear #ParisNeuroscience community, here is the schedule of the upcoming 'Neural Networking Night' season !
September 3, 2025 at 8:46 AM
Reposted by Desdemona Fricker
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.
September 19, 2025 at 1:01 PM
Reposted by Desdemona Fricker
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
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...
www.nature.com
September 17, 2025 at 8:12 PM
Reposted by Desdemona Fricker
🚨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...
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...
www.biorxiv.org
September 16, 2025 at 3:56 PM
Reposted by Desdemona Fricker
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.
🎨🔬 Quand l’art rencontre la science !

Le SPPIN est heureux de vous annoncer l'Expo #SciArt “Regards Croisés” avec l’artiste Sophie Sainte-Marie-Heim et notre collègue @desdemonafricker.bsky.social

🗓 22–28 sept. 2025
📍 Capitainerie de l’Isle, 26 rue Chanoinesse, Paris 4e

Venez nombreux !
July 24, 2025 at 9:33 AM
Reposted by Desdemona Fricker
*New preprint from the lab* – “Granularity of thalamic head direction cells”
doi.org/10.1101/2025...
🧠📈 🧪
1/11
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...
doi.org
September 15, 2025 at 3:13 PM
Reposted by Desdemona Fricker
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
September 11, 2025 at 1:23 PM
Reposted by Desdemona Fricker
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/
September 11, 2025 at 8:14 PM
Reposted by Desdemona Fricker
Two flagship papers from the International Brain Laboratory, now out in ‪@Nature.com‬:
🧠 Brain-wide map of neural activity during complex behaviour: doi.org/10.1038/s41586-025-09235-0
🧠 Brain-wide representations of prior information in mouse decision-making: doi.org/10.1038/s41586-025-09226-1 +
September 3, 2025 at 4:22 PM
Reposted by Desdemona Fricker
The main project from my PhD, in collaboration with Manuela Allegra and @schlab.bsky.social is now available as a preprint! We wondered how the hippocampus and the visual cortex may differ in the way they refine sensory inputs into internal representations
Task engagement differentially drives hippocampal and neocortical neural codes
Sensory inputs are progressively transformed into internal representations of the environment along the cortical hierarchy. How does the behavioral relevance of these inputs affect this encoding? Usin...
www.biorxiv.org
July 1, 2025 at 8:58 AM
Reposted by Desdemona Fricker
🎨🔬 Quand l’art rencontre la science !

Le SPPIN est heureux de vous annoncer l'Expo #SciArt “Regards Croisés” avec l’artiste Sophie Sainte-Marie-Heim et notre collègue @desdemonafricker.bsky.social

🗓 22–28 sept. 2025
📍 Capitainerie de l’Isle, 26 rue Chanoinesse, Paris 4e

Venez nombreux !
July 23, 2025 at 9:50 AM
Reposted by Desdemona Fricker
🚨PhD student position in #cognitive_psychology and #neuroscience, on a project directed by André Knops and in collaboration with the Dugué Lab!

@upcite.bsky.social | @cnrs.fr

Funded by the @agencerecherche.bsky.social (Agence nationale de la recherche)

www.linkedin.com/jobs/view/42...
Université Paris Cité hiring Doctoral Student in Paris, Île-de-France, France | LinkedIn
Posted 1:38:05 PM. PhD Student Position at University Paris CitéIn the context of a collaborative project involving…See this and similar jobs on LinkedIn.
www.linkedin.com
July 21, 2025 at 2:10 PM
Reposted by Desdemona Fricker
📣 We are expanding! Repost 🙏🏽

- Postdoc (funded by @simonsfoundation.org grant on synchronisation between cognitive representations and stepping)
- Project Associates
- Create your role! (Reach out if you are keen on these topics and these roles do not define you 👀🤗)

www.neuroact.in
August 1, 2025 at 12:22 PM
Reposted by Desdemona Fricker
Remote activation of place codes by gaze in a highly visual animal www.nature.com/articles/s41... - very cool study with chickadees!
Remote activation of place codes by gaze in a highly visual animal - Nature
Place cells in the chickadee hippocampus coherently represent locations in space, whether physically visited or viewed, enabling spatial reasoning at a distance through a unified process coordinated b...
www.nature.com
July 24, 2025 at 10:57 AM
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.
🎨🔬 Quand l’art rencontre la science !

Le SPPIN est heureux de vous annoncer l'Expo #SciArt “Regards Croisés” avec l’artiste Sophie Sainte-Marie-Heim et notre collègue @desdemonafricker.bsky.social

🗓 22–28 sept. 2025
📍 Capitainerie de l’Isle, 26 rue Chanoinesse, Paris 4e

Venez nombreux !
July 24, 2025 at 9:33 AM
Reposted by Desdemona Fricker
1/3) This may be a very important paper, it suggests that there are no prediction error encoding neurons in sensory areas of cortex:

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

I personally am a big fan of the idea that cortical regions (allo and neo) are doing sequence prediction.

But...

🧠📈 🧪
Sensory responses of visual cortical neurons are not prediction errors
Predictive coding is theorized to be a ubiquitous cortical process to explain sensory responses. It asserts that the brain continuously predicts sensory information and imposes those predictions on lo...
www.biorxiv.org
July 11, 2025 at 3:45 PM
Reposted by Desdemona Fricker
New work! Learning is assumed to involve synaptic plasticity, but which specific synapses change to enable higher order cognitive functions? We actually find that cognitive flexibility involves potentiation of long-range GABAergic synapses from prefrontal PV neurons: www.biorxiv.org/content/10.1...
Synaptic plasticity of prefrontal long-range inhibition regulates cognitive flexibility
While glutamatergic synaptic plasticity is believed to be a fundamental mechanism mediating learning, the behavioral significance of plasticity at cortical GABAergic synapses remains less well underst...
www.biorxiv.org
June 30, 2025 at 5:55 PM
Reposted by Desdemona Fricker
Great wave of @agencerecherche.bsky.social results for SPPIN ! Congrats to our researchers & their amazing partners!

@desdemonafricker.bsky.social : HDNavigGO
@npanayotis.bsky.social : ReGeNeRETT
G. Caron: MNIONALS (JCJC)
@brandonstell.bsky.social : AdaptingMovement

@cnrs.fr @upcite.bsky.social
July 11, 2025 at 2:41 PM