Document Type
Article
Publication Date
8-19-2024
Abstract
The dorsal funiculus in the spinal cord relays somatosensory information to the brain. It is made of T-shaped bifurcation of dorsal root ganglion (DRG) sensory axons. Our previous study has shown that Slit signaling is required for proper guidance during bifurcation, but loss of Slit does not affect all DRG axons. Here, we examined the role of the extracellular molecule Netrin-1 (Ntn1). Using wholemount staining with tissue clearing, we showed that mice lacking Ntn1 had axons escaping from the dorsal funiculus at the time of bifurcation. Genetic labeling confirmed that these misprojecting axons come from DRG neurons. Single axon analysis showed that loss of Ntn1 did not affect bifurcation but rather altered turning angles. To distinguish their guidance functions, we examined mice with triple deletion of Ntn1, Slit1, and Slit2 and found a completely disorganized dorsal funiculus. Comparing mice with different genotypes using immunolabeling and single axon tracing revealed additive guidance errors, demonstrating the independent roles of Ntn1 and Slit. Moreover, the same defects were observed in embryos lacking their cognate receptors. These in vivo studies thus demonstrate the presence of multi-factorial guidance mechanisms that ensure proper formation of a common branched axonal structure during spinal cord development.
Recommended Citation
Curran, Bridget M.; Nickerson, Kelsey R.; Yung, Andrea R.; Goodrich, Lisa V.; Jaworski, Alexander; Tessier-Lavigne, Marc; and Ma, Le, "Multiple Guidance Mechanisms Control Axon Growth to Generate Precise T-Shaped Bifurcation During Dorsal Funiculus Development in the Spinal Cord" (2024). Farber Institute for Neuroscience Faculty Papers. Paper 63.
https://jdc.jefferson.edu/farberneursofp/63
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.
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PubMed ID
39159057
Language
English
Comments
This article is the author's final published version in eLife, Volume 13, August 2024.
The published version is available at https://doi.org/10.7554/eLife.94109.
Copyright © Curran et al.