Professor of Neurosciences (PR1) - Université de Bordeaux
Contact:
denis.combes@u-bordeaux.fr
+33 (0)5 57 57 45 60
Site : Carreire
Team:
Motor neuron and synaptic partners (Motoneurone et partenaires synaptiques - MotoPSyn)
Domain:
Integrative Neurosciences
Research axis:
- Motor systems/Development
- Motor systems/Locomotion
Scientific expertise:
- Motor networks (locomotion)
- Neuromodulation of neural networks
- Sensorimotor integration
- Metamorphosis
Projects:
- Short and long-term plasticity of locomotor networks during development. The aim of this project is to establish the neural substrates underlying the structural and functional changes of spinal locomotor networks during development and to determine to what extent these alterations are under the influence of neuromodulatory afferents from the brainstem and sensory feedback. Our model is the frog Xenopus laevis which metamorphosis includes a complete transformation of the animal’s biomechanical apparatus as it changes its locomotory strategy from axial-based undulatory swimming using alternating contractions of left and right trunk muscles, to bilaterally-synchronous kicking of the newly developed hindlimbs in the young adult. At critical stages during this behavioral switch, functional larval and adult locomotor systems co-exist in the same animal, implying a progressive and dynamic reconfiguration of underlying spinal circuitry and neuronal properties as limbs are added and the tail regresses.
- Developmental adaptation of networks controlling locomotion and gaze during metamorphosis. We investigate the functional interactions between the central networks responsible for two distinct behavioural tasks (locomotion and gaze control), and have revealed for the first time that intrinsic feed-forward signals from the spinal locomotor central pattern-generator interact with extraocular motor circuitry to participate to gaze stabilization. We want to answer the following questions: i) what are the neural pathways and mechanisms underlying these interactions between oculomotor and locomotor networks? 2) How the efferent copy from the locomotor network interacts with vestibular and visual inputs which are also involved in gaze adjustment? 3) How do these interactions locomotion / gaze control adapt during the radical change in locomotor strategy during metamorphosis (from undulatory swimming to limb propulsion)?