Begbie J, Graham A
MRC Centre for Developmental Neurobiology, Guy's Campus, King's College London, London SE1 9RT, UK.
Philos Trans R Soc Lond B Biol Sci. 2001 Oct 29;356(1414):1655-60. doi: 10.1098/rstb.2001.0920.
The ectodermal placodes are focal thickenings of the cranial embryonic ectoderm that contribute extensively to the cranial sensory systems of the vertebrates. The ectodermal placodes have long been thought of as representing a coherent group, which share a developmental and evolutionary history. However, it is now becoming clear that there are substantial differences between the placodes with respect to their early development, their induction and their evolution. Indeed, it is now hard to consider the ectodermal placodes as a single entity. Rather, they fall into a number of distinct classes and it is within each of these that the members share a common development and evolution.
外胚层基板是颅胚胎外胚层的局灶性增厚，对脊椎动物的颅感觉系统有广泛贡献。长期以来，外胚层基板一直被认为是一个连贯的群体，它们有着共同的发育和进化历史。然而，现在越来越清楚的是，基板在其早期发育、诱导和进化方面存在重大差异。事实上，现在很难将外胚层基板视为一个单一的实体。相反，它们分为若干不同的类别，每个类别中的成员都有共同的发育和进化过程。
