PUBLICATION
Pathfinding by zebrafish motoneurons in the absence of normal pioneer axons
- Authors
- Pike, S.H., Melançon, E.F., and Eisen, J.S.
- ID
- ZDB-PUB-961014-881
- Date
- 1992
- Source
- Development (Cambridge, England) 114: 825-831 (Journal)
- Registered Authors
- Eisen, Judith S., Melançon (Brandenburg), Ellie
- Keywords
- none
- MeSH Terms
-
- Animals
- Axons/physiology
- Methods
- Microscopy, Fluorescence
- Motor Neurons/cytology
- Motor Neurons/physiology*
- Neural Pathways/embryology*
- Zebrafish/embryology*
- PubMed
- 1618146 Full text @ Development
Citation
Pike, S.H., Melançon, E.F., and Eisen, J.S. (1992) Pathfinding by zebrafish motoneurons in the absence of normal pioneer axons. Development (Cambridge, England). 114:825-831.
Abstract
Individually identified primary motoneurons of the zebrafish embryo pioneer cell-specific peripheral motor nerves. Later, the growth cones of secondary motoneurons extend along pathways pioneered by primary motor axons. To learn whether primary motor axons are required for pathway navigation by secondary motoneurons, we ablated primary motoneurons and examined subsequent pathfinding by the growth cones of secondary motoneurons. We found that ablation of the primary motoneuron that pioneers the ventral nerve delayed ventral nerve formation, but a normal-appearing nerve eventually formed. Therefore, the secondary motoneurons that extend axons in the ventral nerve were able to pioneer that pathway in the absence of the pathway-specific primary motoneuron. In contrast, in the absence of the primary motoneuron that normally pioneers the dorsal nerve, secondary motoneurons did not pioneer a nerve in the normal location, instead they formed dorsal nerves in an atypical position. This difference in the ability of these two groups of motoneurons to pioneer their normal pathways suggests that the guidance rules followed by their growth cones may be very different. Furthermore, the observation that the atypical dorsal nerves formed in a consistent incorrect location suggests that the growth cones of the secondary motoneurons that extend dorsally make hierarchical pathway choices.
Genes / Markers
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Orthology
Engineered Foreign Genes
Mapping