Wilson S W, Easter S S
Department of Biology, University of Michigan, Ann Arbor 48109-1048.
Proc Natl Acad Sci U S A. 1991 Mar 15;88(6):2293-6. doi: 10.1073/pnas.88.6.2293.
During development of the nervous system, growth cones navigate very precisely to their appropriate, often distant, targets. In insects, the task of establishing the earliest pathways is accomplished by a small number of neurons, termed pioneers. These neurons have axons that lay down an early scaffold, which provides a substrate for many later-developing axons. Here we show that a similar type of cell exists in the embryonic vertebrate brain. Using light- and electron-microscopic techniques we have examined the formation of one of the earliest tracts in the zebrafish brain. We find that it is pioneered at a precise time by the growth cone of a single neuron present in a predictable location. These observations show a fundamental similarity in the establishment of axonal pathways in the central nervous systems of both invertebrates and vertebrates.
在神经系统发育过程中，生长锥会非常精确地导航至其合适的目标，这些目标往往距离较远。在昆虫中，建立最早通路的任务由少数被称为先驱神经元的神经元完成。这些神经元的轴突形成一个早期支架，为许多后来发育的轴突提供了底物。在这里，我们表明在胚胎脊椎动物大脑中存在类似类型的细胞。利用光学和电子显微镜技术，我们研究了斑马鱼大脑中最早的神经束之一的形成。我们发现，在可预测的位置存在的单个神经元的生长锥在精确的时间率先形成该神经束。这些观察结果表明，在无脊椎动物和脊椎动物的中枢神经系统中，轴突通路的建立存在根本的相似性。
