Gating of spinal-efferent copy signal and sensory signals for gaze control during locomotion – LOCOGATE

As a result of a previous ANR project, the 2 involved teams could demonstrate the existence of a spino-extraocular motor coupling in 2 animal models: the xenopus and the mouse. The present proposal, will define the role and prevalence in the control of gaze of efferent copies, and their relation to online visuo-motor strategies. Specifically, we will investigate 2 working hypotheses which postulate first that the context-dependent contributions of sensory signals and spino-extraocular efferent signals to gaze control critically depend on species-specific locomotor parameters. Second, we postulate that sensory feedbacks and spinal efference copy signals might be differentially integrated by subpopulations of central vestibular nuclei neurons. Understanding interaction between sensory signals and efference copies in a simple circuit like 3D eye movements in animal models constitutes a great advantage to better characterize sensorimotor functions at the circuit & microcircuit levels as well as the underlying neural computations. This project will employ an appropriate "evolution-development" amphibian model and a mammalian model, both allowing complementary neurobiological integrative analysis, in a phylogenic and develomental context. Both partners have already collaborated on different topics including the study of spinal efferent copies, they have long common track record of collaborations and all the expertise required to reach the scientific objectives. During this project, all efforts will be made to minimize the use and suffering of animals, in accordance with the European guidelines on animal care. While this project is using animal models, the understanding of the coupling between spinal locomotor networks and the brain is an essential question for rehabilitation research on humans. Understanding which signals are used and the role of efferent copies is indeed essential to favor accurate rehabilitation strategies in situation where patients suffers from sensory or cortical motor control loss.