[Molecular control of ventro-dorsal polarization of the spinal neural tube in vertebrates]

The embryonic neural tube gives rise to the whole central nervous system (CNS) in vertebrates. The establishment of a dorsoventral axis in the neural tube is one of the first step to achieve the polarisation observed in the adult CNS: the dorsal aspect of it receives sensory inputs from the periphery and in response, the ventral aspect sends signals by motor cells: the motor neurones. This polarization is induced early in embryonic development by the signals secreted by polarizing centres such as the roof plate and the floor plate (e.g. BMP and Sonic Hedgehog). Since the neuroepithelium is sensitive to these signals, these cells respond by expressing sets of transcription factors in specific domains. Different combinations of transcription factors create progenitor domains that eventually give rise to post-mitotic neurones of different subtype in the dorso-ventral axis of the neural tube.