G protein-independent mechanisms are critical for odorant receptor-induced regulation of axonal wiring in the olfactory system.

Abstract

Event Abstract Back to Event G protein-independent mechanisms are critical for odorant receptor-induced regulation of axonal wiring in the olfactory system. Kiavash Movahedi1, 2*, Xavier Grosmaitre3 and Paul Feinstein4 1 Vrije Universiteit Brussel - VIB, Myeloid Cell Immunology laboratory, Belgium 2 Max Planck Institute of Biophysics, Germany 3 Centre des Sciences du Goût et de l'Alimentation, France 4 Hunter College, United States Odorant receptors (ORs) regulate the axonal identity and glomerular formation of olfactory sensory neurons (OSNs). The mechanisms of OR-induced axon guidance remain enigmatic, but have been suggested to fully rely on G-protein signaling. Using G protein-coupling mutations in ORs via gene targeting, we now show that G-protein signaling is mainly required to promote OSN maturation and concomitant axon outgrowth. OSNs expressing signaling-deficient ORs remained immature and were unable to extend axons to the olfactory bulb. Neuronal maturation and axonal projections could be rescued via two complementary approaches: by the expression of a constitutively active G-protein mutant or through to the global co-expression of a second functional OR in all OSNs. In the latter approach, the forced expression of an OR did not suppress endogenous OR gene choice, even though the exogenous OR expression levels were high enough to support neuronal activity, alter the glomerular map and rescue the maturation and axonal projections of signaling-deficient ORs and a vomeronasal receptor expressed in OSNs. Our results show that while the OR was a critical determinant of axonal identity, the G-protein signaling capacity of OSNs did not correlate with the position of axonal convergence, indicating that the core determinants of axonal identity and anterior-posterior targeting relied on G protein-independent mechanisms. This was further corroborated by a new strategy to stochastically alter the levels of G-protein signaling in OSNs expressing functional ORs. Together, our results indicate that ORs rely on the interplay of distinct mechanistic pathways to regulate the development of the olfactory map. Keywords: Olfaction, odorant receptor, axon guidance, neuronal wiring, Olfactory receptor gene choice, G protein-coupled receptor, G-protein signaling, cAMP; Neurogenetics, Gene Choice, Singular Expression, Axon identity, Brainbow Conference: 11th National Congress of the Belgian Society for Neuroscience, Mons, Belgium, 22 May - 22 May, 2015. Presentation Type: Oral or Poster presentation Topic: Neuroscience Citation: Movahedi K, Grosmaitre X and Feinstein P (2015). G protein-independent mechanisms are critical for odorant receptor-induced regulation of axonal wiring in the olfactory system.. Front. Neurosci. Conference Abstract: 11th National Congress of the Belgian Society for Neuroscience. doi: 10.3389/conf.fnins.2015.89.00013 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 05 May 2015; Published Online: 05 May 2015. * Correspondence: Dr. Kiavash Movahedi, Vrije Universiteit Brussel - VIB, Myeloid Cell Immunology laboratory, Brussel, 1050, Belgium, kiavash.movahedi@vub.ac.be Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Kiavash Movahedi Xavier Grosmaitre Paul Feinstein Google Kiavash Movahedi Xavier Grosmaitre Paul Feinstein Google Scholar Kiavash Movahedi Xavier Grosmaitre Paul Feinstein PubMed Kiavash Movahedi Xavier Grosmaitre Paul Feinstein Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.