Présentation

Dynamic and Pathophysiology of Neuronal Networks

Principal Investigator: Laurent Venance, DR1 Inserm

We are focusing our research on the procedural learning, which corresponds to the acquisition of skills through repeated performance, such as biking or playing an instrument. Cortex-basal ganglia loops (Fig.1a) are involved in the adaptive control of behavior and are the main substrate for procedural learning. Our main focus is about the role of the striatum, which acts as a coincidence detector of distributed patterns of cortical and thalamic activity and is in charge to extract pertinent information from background noise at a t time in a given situation, which will give rise to an action in adequation with the environment (Fig.1b). Our aim is to investigate the biological processes at play to set the striatal filter which allows this proper signal/noise detection. The strenght of the striatal filter depends mainly on the cortico- and thalamo-striatal synaptic efficacy changes. Cortico- and thalamo-striatal long-term plasticity provides a fundamental mechanism for the function of the basal ganglia in in procedural learning. We thus characterize striatal plasticity repertoire and maps at play in physiological and pathophysiological conditions ex vivo and in behaving mice, using a set of highly resolutive techniques combining ex vivo and in vivo electrophysiology, optogenetics, 2-photon imaging, computational models.

Laurent Venance illustration
Fig. 1 : Basal ganglia and procedural learning. a) Basal ganglia circuits; highlight on the two trans-striatal, direct and indirect, pathways. b) Striatum extracts pertinent information from background noise, and is engaged in fast learning, goal directed behavior and habit formation.
Long-term synaptic plasticity and neuromodulation (e.g. dopamine, acetylcholine, GABA or BDNF) occurs at each step (arrow