Chronology-based architecture of descending circuits that underlie the development of locomotor repertoire after birth
- Janelia Research Campus, Howard Hughes Medical Institute, United States
Abstract
The emergence of new and increasingly sophisticated behaviors after birth is accompanied by dramatic increase of newly established synaptic connections in the nervous system. Little is known, however, of how nascent connections are organized to support such new behaviors alongside existing ones. To understand this, in the larval zebrafish we examined the development of spinal pathways from hindbrain V2a neurons and the role of these pathways in the development of locomotion. We found that new projections are continually layered laterally to existing neuropil, and give rise to distinct pathways that function in parallel to existing pathways. Across these chronologically layered pathways, the connectivity patterns and biophysical properties vary systematically to support a behavioral repertoire with a wide range of kinematics and dynamics. Such layering of new parallel circuits equipped with systematically changing properties may be central to the postnatal diversification and increasing sophistication of an animal's behavioral repertoire.
Data availability
Source data files have been provided for numerical data that are represented as graphs in Figure 3C, 7D, 7E, 7F, 8E, 9J, 9K, 9L, and 10C.
Article and author information
Author details
Funding
Howard Hughes Medical Institute
- Avinash Pujala
- Minoru Koyama
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Ethics
Animal experimentation: All experiments presented in this study were conducted in accordance with the animal research guidelines from the National Institutes of Health and were approved by the Institutional Animal Care and Use Committee and Institutional Biosafety Committee of Janelia Research Campus. (16-145).
Copyright
© 2019, Pujala & Koyama
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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Chronology-based architecture of descending circuits that underlie the development of locomotor repertoire after birth
eLife 8:e42135.
https://doi.org/10.7554/eLife.42135
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