Desdemona Fricker
@desdemonafricker.bsky.social
560 followers 860 following 9 posts
Neuroscientist and Research Director @CNRS. «Orientation&Coordination» team. Head direction, interneurons, memory. Saints-Pères, Paris 👩‍🔬🧠
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Reposted by Desdemona Fricker
sppin-cnrs.bsky.social
Dear #ParisNeuroscience community, here is the schedule of the upcoming 'Neural Networking Night' season !
Reposted by Desdemona Fricker
carlosbrody.bsky.social
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.
desdemonafricker.bsky.social
Thanks to the Capitainerie de l’Isle and to Nathalie for hosting our exhibit ✨
Reposted by Desdemona Fricker
thomas-zhihao-luo.bsky.social
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
Reposted by Desdemona Fricker
apeyrache.bsky.social
🚨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
Reposted by Desdemona Fricker
desdemonafricker.bsky.social
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.
sppin-cnrs.bsky.social
🎨🔬 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 !
Reposted by Desdemona Fricker
jeromeepsztein.bsky.social
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
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.
Reposted by Desdemona Fricker
mace-lab.bsky.social
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/
Reposted by Desdemona Fricker
intlbrainlab.bsky.social
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 +
Reposted by Desdemona Fricker
cantinortiz.bsky.social
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
Reposted by Desdemona Fricker
sppin-cnrs.bsky.social
🎨🔬 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 !
Reposted by Desdemona Fricker
rhythmicspikes.bsky.social
📣 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
desdemonafricker.bsky.social
Thanks to Michael Graupner and the fabulous Orientation and Coordination team 🤩 for sharing the excitement 🥳 and for sharing the Science 🧠
desdemonafricker.bsky.social
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.
sppin-cnrs.bsky.social
🎨🔬 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 !
Reposted by Desdemona Fricker
tyrellturing.bsky.social
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
Reposted by Desdemona Fricker
vikaassohal.bsky.social
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
Reposted by Desdemona Fricker
sppin-cnrs.bsky.social
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
Reposted by Desdemona Fricker
aforli89.bsky.social
Our study is out in Nature!
Using wireless Neuropixels we recorded hippocampal activity in freely flying bats and uncovered replay and theta(less) sweeps, revealing striking differences from classic rodent models.

👉 www.nature.com/articles/s41...
Replay and representation dynamics in the hippocampus of freely flying bats - Nature
Nature - Replay and representation dynamics in the hippocampus of freely flying bats
www.nature.com
Reposted by Desdemona Fricker
beneuroscience.bsky.social
Our new paper out now in Science explores how neural activity in the lateral entorhinal cortex (LEC) *drifts* over time - and *jumps* at key boundaries - to help organize events in memory.

🔗 www.science.org/doi/10.1126/...

Here's a quick summary of what we found 🧵👇
Reposted by Desdemona Fricker