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Netrin/DCC Signaling Guides Olfactory Sensory Axons to Their Correct Location in the Olfactory Bulb

Authors :
Vanisha Lakhina
Christina L. Marcaccio
Michael Granato
Esther Fujimoto
Mark E. Lush
Roshan A. Jain
Xin Shao
Joshua L. Bonkowsky
Jonathan A. Raper
Source :
The Journal of Neuroscience. 32:4440-4456
Publication Year :
2012
Publisher :
Society for Neuroscience, 2012.

Abstract

Olfactory sensory neurons expressing particular olfactory receptors project to specific reproducible locations within the bulb. The axonal guidance cues that organize this precise projection pattern are only beginning to be identified. To aid in their identification and characterization, we generated a transgenic zebrafish line, OR111-7:IRES:Gal4, in which a small subset of olfactory sensory neurons is labeled. Most sensory neurons expressing theOR111-7transgene project to a specific location within the bulb, the central zone protoglomerulus, while a smaller number project to the lateral glomerulus 1 protoglomerulus. Inhibiting Netrin/DCC (deleted in colorectal cancer) signaling perturbs the ability of OR111-7-expressing axons to enter the olfactory bulb and alters their patterns of termination within the bulb. The Netrin receptor DCC is expressed in olfactory sensory neurons around the time that they elaborate their axons, netrin1a is expressed near the medial-most margin of the olfactory bulb, and netrin1b is expressed within the ventral region of the bulb. Loss of Netrin/DCC signaling components causes some OR111-7-expressing sensory axons to wander posteriorly after exiting the olfactory pit, away from netrin-expressing areas in the bulb. OR111-7-expressing axons that enter the bulb target the central zone less precisely than normal, spreading away from netrin-expressing regions. These pathfinding errors can be corrected by the reexpression of DCC withinOR111-7transgene-expressing neurons in DCC morphant embryos. These findings implicate Netrins as the only known attractants for olfactory sensory neurons, first drawing OR111-7-expressing axons into the bulb and then into the ventromedially positioned central zone protoglomerulus.

Details

ISSN :
15292401 and 02706474
Volume :
32
Database :
OpenAIRE
Journal :
The Journal of Neuroscience
Accession number :
edsair.doi.dedup.....7fbac652602afb464f7a3b99e68cf0ae
Full Text :
https://doi.org/10.1523/jneurosci.4442-11.2012