L’identification des réseaux génétiques spécifiant la bordure neurale est un pré-requis indispensable à la compréhension des mécanismes responsables de la formation de la crête neurale.
Le Douarin Nicole, Creuzet Sophie (Gif-sur-Yvette, France), Richman Joy (University of British Columbia, Vancouver, Canada), Rijli Filippo (Friedrich Miescher Institute (FMI), Basel, Switzerland)
Brito Jose (Institute of Neurobiology, Gif-sur-Yvette, France), Bronner-Fraser Marianne (Caltech, California, USA), Chuong Chen-Ming (University of Southern California, California, USA), Creuzet Sophie (Institute of Neurobiology, Gif-sur-Yvette, France), Dupin Elisabeth (Institute of Neurobiology, Gif-sur-Yvette, France), Fraser Scott (Caltech, California, USA), Helms Jill (StanfordUniversity, California, USA), Holland Linda (LaJolla, California, USA), Jeffery William (University of Maryland, Maryland, USA), Kuratani Shigeru (Riken, Japan), Le Douarin Nicole (Collège de France, Académie des Sciences), Martinez Salvador (Institue of Neurosciences, Alicante, Spain), Monsoro-Burq Anne-Hélène (Institut Curie, Orsay, France), Richman Joy (University of British Columbia, Vancouver, Canada), Rijli Filippo (Friedrich Miescher Institute (FMI), Basel, Switzerland), Schlosser Gerhart (University of Bremen, Bremen, Germany), Smith Maya Meredith (Developmental Neurobiology, London), Vernier Philippe (Institute of Neurobiology, Gif-sur-Yvette, France).
“On the trail of the ‘new head’ in Les Treilles, by Marianne Bronner-Fraser
The vertebrate brain develops in association with neighboring tissues: neural crest, placodes, mesoderm and endoderm. The molecular and evolutionary relationships between the forming nervous system and the other craniofacial structures were at the focus of a recent meeting at the Fondation des Treilles in France. Entitled ‘Relationships between Craniofacial and Neural Development’, the meeting brought together researchers working on diverse species, the findings of whom provide clues as to the origin and diversity of the brain and facial regions that are involved in forming the ‘new head’ of vertebrates.
The vertebrate brain develops in close association with neighboring tissues, including cells from the neural crest, mesoderm and endoderm, such that their development is interlinked and interdependent. Together, these tissues form the central and peripheral nervous systems and the craniofacial skeleton of the vertebrate head. A recent meeting at the Fondation des Treilles in Provence, organized by Sophie Creuzet (Institute of Neurobiology, Gif-Sur-Yvette, France), Joy Richman (University of British Columbia, Vancouver, Canada) and Filippo Rijli (Friedrich Miescher Institute, Basel, Switzerland), focused on understanding and highlighting the tissue, cellular, molecular and evolutionary relationships between the forming nervous system and other craniofacial structures.
The ‘new head’, as proposed by Gans and Northcutt (Gans and Northcutt, 1983), is a defining feature of vertebrates, distinguishing them from invertebrate chordates that have a central nervous system (CNS) but lack a complex brain, peripheral ganglia and craniofacial skeleton (see Fig. 1). During development, the vertebrate brain forms from the neural plate, a specialized region of the ectoderm that invaginates to form the neural tube. The edge or ‘border’ of the neural plate contains presumptive neural crest cells that migrate away from the CNS to form peripheral ganglia, craniofacial bone and muscle, pigment cells, and numerous other derivatives. These cells travel through mesodermal tissue and interact with endoderm within the branchial (pharyngeal) arches; these arches, in vertebrates, give rise to jaws, among other structures. Immediately lateral to this tissue is the preplacodal domain, which contains precursors to the ‘ectodermal placodes’. Placodal ectoderm thickens and gives rise to cells that ingress and contribute to neurons of the cranial sensory ganglia. Together with the neural crest, these placodes form the peripheral nervous system of the head. The focus of this meeting was to understand the developmental and evolutionary relationships between these tissues in the building of the new head of vertebrates.