Neuronal integration in the adult mouse olfactory bulb is a non-selective addition process
- Aix-Marseille University, CNRS, France
- Harvard University, United States
- Université Grenoble Alpes, France
Abstract
Adult neurogenesis in the olfactory bulb (OB) is considered as a competition in which neurons scramble during a critical selection period for integration and survival. Moreover, newborn neurons are thought to replace pre-existing ones that die. Despite indirect evidence supporting this model, systematic in vivo observations are still scarce. We used 2-photon in vivo imaging to study neuronal integration and survival. We show that loss of new neurons in the OB after arrival at terminal positions occurs only at low levels. Moreover, long-term observations showed that no substantial cell death occurred at later stages. Neuronal death was induced by standard doses of thymidine analogs, but disappeared when low doses were used. Finally, we demonstrate that the OB grows throughout life. This shows that neuronal selection during OB-neurogenesis does not occur after neurons reached stable positions. Moreover, this suggests that OB neurogenesis does not represent neuronal turnover but lifelong neuronal addition.
Data availability
The raw data that support the findings of this study are several TBs in size and are therefore available on request. A source data file for the main figures has been provided.
Article and author information
Author details
Jean-Claude Platel
Venkatesh N Murthy
Funding
Agence Nationale de la Recherche (ANR-13-BSV4-0013)
- Harold Cremer
Fondation pour la Recherche Médicale (ING20150532361)
- Harold Cremer
Fondation pour la Recherche Médicale (FDT20160435597)
- Harold Cremer
Fondation pour la Recherche Médicale (FTD20170437248)
- Alexandra Angelova
Fondation de France (FDF70959)
- Harold Cremer
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 mice were treated according to protocols approved by the French Ethical Committee (#5223-2016042717181477v2).
Reviewing Editor
- Gary L Westbrook, Oregon Health and Science University, United States
Publication history
- Received: January 2, 2019
- Accepted: July 7, 2019
- Accepted Manuscript published: July 11, 2019 (version 1)
- Version of Record published: July 16, 2019 (version 2)
Copyright
© 2019, Platel et al.
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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Neuronal integration in the adult mouse olfactory bulb is a non-selective addition process
eLife 8:e44830.
https://doi.org/10.7554/eLife.44830
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