Humans and animals’ survival depends on their ability to learn new adaptive behaviors, to adjust them to changes in their environment or occurring in their own body, and, in some cases, to become extremely skilled or efficient at what they do. All these functions depend on intricate interactions between sensory, motor, and more “cognitive” processes. The cortico-striatal system has been linked with learning but its exact contribution to the multiple processes occurring during different forms of learning and adaptation is far from being well understood.
Understanding the function(s) of the cortico-striatal system is important because its dysfunction results in several prevalent brain diseases such as Parkinson’s disease, mental retardation, or hyperactivity disorders that, noticeably, are characterized by a mixture of sensory, motor, and cognitive deficits.
Thus, our team tries to delineate the contribution(s) of the cortico-striatal system during learning and adaptation. We tackle this challenging objective by developing original tasks allowing us to capture and manipulate the behavior of rodents. We combine this behavioral approach with a wide range of system neuroscience techniques (both in vivo during behavior and ex-vivo) and computational/theoretical approaches.
1- What specific changes in the cortico-striatal system are critical for learning and efficient interactions with the environment?
1.1- Rodents rely on their whiskers (among other senses) to perceive the structure of their environment. What changes do occur in the circuits of the primary somatosensory cortex and in its projections to the dorsal striatum during sensorimotor learning and adaptation?
1.2- The dorsal striatum receives inputs from associative, motor, and sensory cortical regions. How are these inputs modified during learning or when animals adapt/optimize a previously learned behavior?
1.3- Several cell types are found in the cortex and striatum (interneurons, projection neurons). What are their respective contribution to learning and behavioral adaptation?
2- What is the function of the dorsal striatum? Theories about the dorsal striatum are related to learning, storage and expression of procedural memories, action selection, decision making, the control of vigor, or the sensitivity to the motor and temporal costs. We’re trying to make sense of these multiple hypotheses.
To better understand the neural and behavioral determinants of sensorimotor learning, we combine a wide range of neuroscience-specific techniques (see below) and the development of customized behavioral tasks. We also use theoretical approaches such as (deep) reinforcement learning and optimal control to model behavioral and neural data and generate new mechanistic hypotheses.