Description du projet
De l’entrée sensorielle aux décisions et à la réaction motrice: les substrats neuronaux
Les organismes multicellulaires utilisent régulièrement des données sensorielles pour prendre des décisions cognitives qui aboutissent finalement à des réactions motrices. La complexité du cerveau et de ses circuits explique le problème que pose la compréhension des différents substrats neuronaux impliqués dans ce processus. Le projet EngineeringPercepts, financé par le Conseil européen de la recherche, étudiera cette question en s’appuyant sur la capacité du rongeur à décider de franchir un espace en détectant son côté opposé à l’aide d’un seul poil de sa moustache. En combinant l’électrophysiologie in vivo, les injections de virus, les outils d’imagerie et de reconstruction personnalisés et les simulations de Monte Carlo, l’équipe étudiera si des neurones spécifiques du cortex sensoriel reçoivent à la fois des informations sur le toucher et le mouvement et si, lorsque les deux entrées coïncident, la réaction neuronale déclenche la décision de franchir le fossé.
Objectif
Understanding how the brain is able to transform sensory input into decisions is one of the major challenges of systems neuroscience. While recording/imaging during sensory-motor tasks identified neural substrates of sensation and action in various cortical areas, the crucial questions of 1) how these correlates are implemented within the underlying neural networks and 2) how their output triggers decisions, will only be answered when the individual functional measurements are integrated into a coherent model of all task-related circuits.
The goal of my proposal is to use the rodent vibrissal system for building such a model in the context of how a tactile-mediated percept is encoded by the interplay between biophysical, cellular and network mechanisms. Specifically, rodents decide to cross a gap when detecting its far side with a single facial whisker. This suggests that whisker contact with the platform, if synchronized with an internal motor signal, triggers the decision. My key hypothesis is that in sensory cortex layer 5 thick-tufted (L5tt) neurons receive touch and motor information via specific pathways that target basal and apical tuft dendrites, respectively. When localizing the far side of the gap, the two inputs coincide and result in burst spiking output to (sub)cortical areas, triggering the gap cross.
To test this hypothesis, I will determine all sensory/motor-related local and long-range inputs/outputs to/from L5tt neurons, measure whisker-evoked responses of these populations and use the data to constrain network simulations of active whisker touch. Using a multidisciplinary approach, combining in vivo electrophysiology, virus injections, custom imaging/reconstruction tools and Monte Carlo simulations, my reverse engineering strategy will provide unmatched mechanistic insight to perceptual decision making and will function as a show case – generalizable across sensory modalities and species – of how to derive computations that underlie behavior.
Champ scientifique
- natural sciencesbiological scienceszoologymammalogyprimatology
- natural sciencesbiological sciencesneurobiology
- natural sciencesbiological sciencesmicrobiologyvirology
- natural sciencesmathematicsapplied mathematicsstatistics and probabilitybayesian statistics
- natural sciencescomputer and information sciencesartificial intelligencecomputational intelligence
Programme(s)
Thème(s)
Régime de financement
ERC-STG - Starting GrantInstitution d’accueil
80539 Munchen
Allemagne