McConnell S K
Vision Center Laboratory, Salk Institute for Biological Studies, San Diego, CA 92138.
Brain Res. 1988 Jan-Mar;472(1):1-23. doi: 10.1016/0165-0173(88)90002-1.
One of the fundamental tasks of neurobiology is to understand how the precision and specificity of the adult nervous system is achieved during development. This paper reviews the progress that has been made toward this end in studies of the developing mammalian cerebral cortex. Particular attention is focused on the problem of how cortical neurons make decisions during development: the correlation between a neuron's 'birthday' and its final laminar destination and projection patterns has raised the possibility that young neurons may be committed to their adult fates very early on in development, perhaps prior to migration. Indeed, several lines of evidence reviewed here suggest that at least some of the decisions made by cortical neurons are intrinsic properties of the cell itself. These studies include experiments on the reeler mouse mutant, and more recent attempts to manipulate developmental fates by pharmacological interventions and transplantation techniques. It is concluded that early commitment events in the cerebral cortex may specify a neuron's laminar position and restrict the range of potential axonal projections that the cell may form, but that local positional cues direct neurons to select (or maintain) only certain of the possible projections.
神经生物学的基本任务之一是了解成年神经系统的精确性和特异性在发育过程中是如何实现的。本文综述了在哺乳动物大脑皮质发育研究中朝着这一目标所取得的进展。特别关注的问题是皮质神经元在发育过程中如何做出决定：神经元的“出生日期”与其最终的层状位置和投射模式之间的相关性，引发了这样一种可能性，即年轻神经元可能在发育早期，也许在迁移之前，就已注定了其成年后的命运。事实上，本文所综述的几条证据表明，皮质神经元做出的至少一些决定是细胞本身的内在特性。这些研究包括对reeler小鼠突变体的实验，以及最近通过药物干预和移植技术操纵发育命运的尝试。得出的结论是，大脑皮质中的早期决定事件可能确定了神经元的层状位置，并限制了细胞可能形成的潜在轴突投射范围，但局部位置线索引导神经元仅选择（或维持）某些可能的投射。
