4/4 Without any explicit “context” label, a neural-network RL agent trained by TD learning reproduces both rule-specific strategies and the remapping. This suggests remapping can emerge from standard learning dynamics via representation change. So remapping may be an emergent property.

3/4 Instead, DA signals are best captured by different RPE-like variables computed over the currently learned action representation, not one fixed RPE. In short: the “error” DA reports changes with how the animal is currently defining the action.

2/4 Same movements, different reward rules in the same mouse. In a self-paced 3-target foraging task in freely moving mice, nucleus accumbens dopamine (fiber photometry) shows rule-dependent remapping. Model comparison suggests a fixed, representation-invariant RPE can’t explain DA across rules.

1/4 When rules change, dopamine (DA) changes what it calls an “action”.
New bioRxiv version: “Dopamine tracks adaptive learning of action representations”.
www.biorxiv.org/content/10.1...
This project brought together Maxime Come’s PhD work and Arnaud Lespart’s postdoctoral work in our lab.

Congratulations Lauren

Sleep-dependent infraslow rhythms are evolutionarily conserved across reptiles and mammals Nature Neuroscience - Bergel et al. show that an infraslow rhythm connecting the brain and body during sleep is shared by lizards, mammals and birds, revealing an ancestral process and reshaping...

⚠️ New paper alert and what a way to end 2025! 🎉
Happy to share our story “Sleep-dependent infraslow rhythms are evolutionarily conserved across reptiles and mammals.” published today in Nature Neuroscience.

Sleeping dragons 🦎 and functional ultrasound!
Read the full paper here: rdcu.be/eWJHb 1/8

Congrats, well deserve

You just finished your PhD and you are looking for a postdoc to study stress-dependent modulation of learning. We are using the powerful fly model to understand the underlying circuits and mechanisms. You can apply here:
emploi.cnrs.fr/Offres/CDD/U...

Lauren Reynolds

Big news for @laurenmac.bsky.social !
2025 is quite a year: CNRS position + ERC Starting Grant
Her project DeMARRe will study how adolescent exploration & risk-taking shape neural circuits and resilience in adulthood.
@cnrs.fr @espciparispsl.bsky.social
www.insb.cnrs.fr/fr/personne/...

Brain Surfaces of 70 primate species

1
To predict the behaviour of a primate, would you rather base your guess on a closely related species or one with a similar brain shape? We looked at brains & behaviours of 70 species, you’ll be surprised!

🧵Thread on our new preprint with @r3rt0.bsky.social , doi.org/10.1101/2025...

Alcool et nicotine : un même circuit cérébral à l’origine de la récompense et de l’anxiété

👋 @cnrs-paris.bsky.social @espciparispsl.bsky.social
✍️ @faurelab.bsky.social & Fabio Marti
👉 Lire l'article dans buff.ly/vE1j6LP
buff.ly/fD5DOxu

Congratulations to first author Tinaïg Le Borgne for her outstanding work and Fabio marti for leading this project. Many thanks as well to our collaborators across @espciparispsl.bsky.social , @cnrsbiologie.bsky.social, @sorbonne-universite.fr and beyond!

Nicotine and alcohol seem very different, but they converge on the same circuit. Both activate NAc-projecting dopamine neurons and inhibit those projecting to the amygdala. We show that this shared loop shapes reward and emotion, helping explain their high co-use.

A circuit-level explanation for nicotine’s dual impact: Nicotine activates VTA→NAc dopamine neurons (reward), but this comes at a cost: It triggers a GABAergic feedback loop that inhibits VTA→amygdala neurons (emotion).
One drug, the dopaminergic circuits, 2 effects: reinforcement + negative affect.

Nicotine engages a VTA-NAc feedback loop to inhibit amygdala-projecting dopamine neurons and induce anxiety-like behaviors - Nature Communications Drugs of abuse exert both motivational and emotional effects. Here, the authors show that nicotine and ethanol activate a VTA–NAc loop that inhibits dopamine neurons projecting to the amygdala, thereb...

Nicotine doesn’t just “turn on” the brain’s reward circuits — it reshapes them. Our new paper in Nature Communications shows that activating reward-linked dopamine neurons also sets off a feedback loop that drives negative emotional states.
www.nature.com/articles/s41...

Slowing the drive: A new regulatory break for nicotine reward-related behaviors In this issue of Neuron, Jehl et al. developed a “suicide” antagonist to demonstrate that the interpeduncular nucleus acts as a regulatory controller of nicotine reward-related behavior through connec...

Our work on the role of the interpeduncular nucleus in nicotine reward ( www.cell.com/neuron/abstr... ) is featured in a Neuron Preview ! Brandon J Henderson highlights how a new regulatory circuit controlling nicotine reinforcement has been uncovered. www.cell.com/neuron/abstr...

Yesss! So happy to see this, totally deserved!

Embodiment of an artificial limb in mice Body ownership disorders can be triggered by disease or body damage in humans. This study shows, using an automated, videography-based procedure, that mice also display quantifiable behavioral markers...

Our work on rubber hand embodiment in mice is out @plosbiology.org! We show that just like in humans, visuo-tactile pairing can lead mice to an embodiment-like behavior with respect to an artificial limb.

Direct and indirect striatal projecting neurons exert strategy-dependent effects on decision-making In the dorsomedial striatum, d-SPNs increase risk seeking, while iSPNs amplify the value of large gains in decision making.

Nouvel article avec mes ami-es belges E. Chaves et A. de Kerchove où on décrit l'effet de l'activation de populations de neurones du striatum sur les stratégies de décision. On a essayé de sortir d'une définition "par l'expérimentateur" de la performance des souris.

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

Sequential and independent probabilistic events regulate differential axon targeting during development in Drosophila melanogaster Nature Neuroscience - The developmental origin of behavioral individuality is unclear. The authors show that a temporal sequence of genetically encoded stochastic mechanisms explains variation in...

Hot off the press:
The excellent Maheva Andriatsilavo and colleagues show how a temporal sequence of stochastic molecular mechanisms allow the emergence of stereotyped individualised neuronal circuits. Just published in Nature Neuroscience:
rdcu.be/ek010

I have an opening in my lab for a postdoctoral fellow to work on projects that relate to the mechanisms of neurotransmitter release by dopamine neurons and/or on how inflammatory signals infuence the functionning of these neurons. Please share.

free access here authors.elsevier.com/c/1kzRE3BtfH...

Congrat J. Jehl, M. Ciscato, E. Vicq & @nicolasguyon.bsky.social . Thanks to our amazing team, and collaborators! @cnrsbiologie.bsky.social , @inserm.fr , @sorbonne-universite.fr , @espciparispsl.bsky.social , @institutpasteur.bsky.social, @frm-officiel.bsky.social

This was made possible by a new chemogenetic method: a covalently tethered suicide antagonist for β4* nAChRs. Sustained, subtype-specific silencing in vivo, with single-site precision. A method developed by Alexandre Mourot in the lab @faurelab.bsky.social

The interpeduncular nucleus blunts the rewarding effect of nicotine Nicotine activates the dopamine reward system to promote consumption and addiction, but the brain has a natural brake to counteract it. Jehl, Ciscato, Vicq, Guyon, et al. identified the interpeduncula...

The interpeduncular nucleus (IPN) dampens nicotine reward via β4* nAChRs and IPN→LDTg projections. Blocking this pathway enhances VTA responses and CPP: A nicotine-specific brake embedded in the mesolimbic system.
New paper from the lab out in @cp-neuron.bsky.social www.cell.com/neuron/abstr...

Registrations for the Symposium for the Biology of decision making (SBDM) in Lyon 2025 are finally open! sbdm2025.github.io Please spread the message!

Social structures are dynamic: manipulating dopamine activity reshapes role distribution, confirming a feedback loop where social context modulates neural states, which in turn reinforce specialization.

A reinforcement learning model reveals how competition for ressources drives behavioral specialization, with varying degrees of exploitation shaping social roles development and driving sex differences.

Neural and computational analyses during the task reveal that dopaminergic activity in the ventral tegmental area (VTA) plays a key role in stabilizing social roles.

Males exhibit clear divisions of labor, where worker-scrounger equilibria emerge from competitive dynamics. In contrast, females adopt more uniform & cooperative behaviors. These sex-specific differences arise only in group contexts—when tested alone, males and females show only subtle differences!