[Neurosurgical embryology. Part 5: Temporal landmarks of the development of the central nervous system in humans].
The establishment of temporal landmarks of the development of the central nervous system was the primary goal of early human embryologists. The description of these landmarks has lost much of its interest since it is now largely accepted that the temporal profile of development is at best a poor indicator of the origin of malformative syndromes. However, we propose here a rapid review describing the principal data available. One of our goals is to present here the original data that are needed to understand the morphological aspect of the development of the central nervous system. The most important results are the presence of a developmental gradient within each anatomical area. This means that all the neurons of a specific anatomical region are not generated at the same time. There is also another gradient that could be described. This gradient is the rostro-caudal gradient: the spinal cord develops first, then the brain stem, and finally the encephalon. This rule is only a general rule with many exceptions like, for instance, the cerebellum that is a late derivative of the neural tube.
Catala
M
M
Laboratoire d'histologie et Embryologie et UMR CNRS 7000, Faculté de Médecine Pitié-Salpêtrière-Université Paris 6. catala@ext.jussieu.fr
D002490:Central Nervous System / Q000033:anatomy & histology / Q000196:embryology* / Q000601:surgery; D004626:Embryology; D006801:Humans; D009493:Neurosurgery