Mechanisms of neural specification from embryonic stem cells.

While embryonic stem (ES) cells have been used for several years to generate specific populations of neural cells in a translational perspective, they have also emerged as a promising approach in developmental neurobiology, by providing reductionist models of neural development. Here we review recent work that indicates that ES-based models are not only able to mimic normal brain development, but also provide novel tools to dissect the relative contribution of intrinsic and extrinsic mechanisms of neural specification. These have thus not only revealed insights on early steps such as neural induction and regional patterning, but also temporal specification of distinct neuronal subtypes, as well as the later acquisition of more complex features such as cytoarchitecture and hodological properties. 2009 Elsevier Ltd. All rights reserved.