title: A pioneering growth cone in the embryonic zebrafish brain.
abstract: 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.
authors.affiliation: Department of Biology, University of Michigan, Ann Arbor 48109-1048.
authors.forename: S W
authors.initials: SW
authors.lastname: Wilson
authors.forename: S S
authors.initials: SS
authors.lastname: Easter
mesh_terms: D000818:Animals; D001369:Axons / Q000648:ultrastructure*; D001921:Brain / Q000166:cytology / Q000196:embryology* / Q000648:ultrastructure; D004625:Embryo, Nonmammalian; D009474:Neurons / Q000648:ultrastructure*; D015027:Zebrafish / Q000196:embryology*