Biology subjects

Perisse, E.

Publications and source records attributed to Perisse, E..

3 recordsLinked to original sources

bioRxiv2026

Acute hypercapnic stress modulates innate and learned defensive behavior

Survival depends on avoiding threats, a process shaped by experience and internal states. Notably, acute stress can induce analgesia, yet the neural mechanisms by which stress alters aversive value coding remain unclear. Using Drosophila, we show that prior noxious experience induces intensity-dependent analgesia and triggers the release of CO2, a known stress signal. Surprisingly, this effect is mediated by tracheal dendrite (td) neurons in the respiratory system rather than classic olfactory pathways. We then demonstrated that activation of td neurons induces analgesia, whereas their inhibition suppresses it and restores normal nocifensive and learned behavior. Finally, high CO2 exposure decreases dopaminergic neuron responses to electric shocks, thereby impairing aversive memory formation. Together, we propose that under hypercapnic (high CO2) stress, td neurons modulate nociceptive computation and aversive value coding in the brain to facilitate appropriate innate and learned behavioral responses.

neuroscience↗

bioRxiv2024

D2-expressing neurons of the anterior paraventricular nucleus of the thalamus modulate learned aversive and safety salience

Associative learning provides a means to assign appropriate value signals to experiences that animals can later use to make appropriate value-based choices. By generalizing from prior aversive experiences and comparing with a current experience, animals can learn the relative aversive ("better or worse than") value or relative positive safety value between experiences. Yet, how such relative value signals are acquired during learning remain poorly known. The paraventricular nucleus of the thalamus (PVT) is critical for the control of salience and valence signals. It is therefore well-placed to be involved in learning relative aversive value and learned safety. Using a newly-developed conditioned place preference task, we uncover specific behavioral signatures associated with learning relative aversive value and learned safety, and related value-based choices. We then show that neurons expressing dopamine D2 receptor (D2+) in the anterior PVT (aPVT) are preferentially recruited by both relative aversive value learning and learned safety. Using a pharmacogenetic strategy, we demonstrate that aPVT D2+, but not D2-, neurons are involved in learning relative- but not absolute- aversive value. Finally, we show that aPVT D2+, but not D2-, neurons are also critical for the encoding of learned safety. Overall, our findings reveal a novel role of aPVT D2+ neurons in computing relative aversive/safety value signals between experiences during learning to promote appropriate value-based choices.

animal behavior and cognition↗

bioRxiv2022

Different dopaminergic neurons signal absolute and relative aversive value in the Drosophila mushroom body.

Animals use prior experience to assign absolute (good or bad) and also relative (better or worse) value to new experience. These learned values guide appropriate later decision-making. While our understanding of how the dopaminergic system computes absolute value is relatively advanced, the mechanistic underpinnings of relative valuation are unclear. Here we reveal mechanisms of absolute and relative aversive valuation in Drosophila. Three types of punishment-sensitive dopaminergic neurons (DANs) drive intensity-scaled plasticity at their respective mushroom body output neuron (MBON) connections to code absolute aversive value. In contrast, by comparing current and previous aversive experiences the MBON-DAN network can code relative aversive value by recruiting a specific subtype of reward-coding dopaminergic neurons which assigns a better than value to the lesser of two aversive experiences. This study therefore provides an important functional consequence of having opposing populations of DANs and illustrates how these can operate together as a system within the MB network to code and compare sequential aversive experience to learn relative aversive value.

neuroscience↗