Alain Chédotal

Introduction

Nervous systems are composed of a network of synaptic connections among excitable cells, neurons. This network develops as axons extend from presynaptic neurons and grow often long distances to reach their correct postsynaptic partners. Neuronal migration and myelination are also key processes for the formation and stabilization of neuronal connections. For years, neurobiologists have tried to uncover the mechanisms controling axon guidance. It was found that these are highly conserved between neurons and during evolution. It was also shown that axonal connections are plastic and can be modified during normal physiological processes and in pathological conditions.

There is mounting evidence suggesting that axon guidance errors occuring during development, are responsible for neurological deficits in particular in the visual system.
The goal of Alain Chedotal’s research is to understand how growing axons and migrating neurons are guided in the brain, since their origin to their target. He is also working on new technologies allowing the visualization of developing neurons and trying to understand the myelination process.

Projects

More precisely, Alain Chédotal and his team are working along four lines of research :

1/ analysis of the role of guidance molecules in neuronal connections : they particularly study axon growth at the central nervous system midline (notably the optic chiasma in the visual system)

2/ utilization of new microscopy analysis methods to study the organizations of neuronal connections in sensorial nervous systems (visual and auditory)

3/ study of the function of axonal guidance molecules (in particular slits and semaphorins) in the control of neuronal migration control during development and in the adult brain. They are trying to determine whether those molecules control neural stem cell migration in normal and/or pathological conditions

4/ study of the role of axonal guidance molecules in the process of myelination. They are developing new methods in video-microscopy to study myelination.

Impacts

The discovery of neural stem cells in the adult brain was a major finding of the recent years. In many models of lesion of the nervous system, neural stem cells can be derived from their usual migration pathway to integrate the injured region. Alain Chedotal and his team are characterizing new molecules controlling neural stem cell development and physiology and determine their ability to promote the regenerative potential of neural on stem cells. These studies could lead to the development of new therapeutic tools to stimulate stem cell migration and differentiation in the visual system.