The role of calretinin-expressing granule cells in olfactory bulb functions and odor behavior.

TitleThe role of calretinin-expressing granule cells in olfactory bulb functions and odor behavior.
Publication TypeJournal Article
Year of Publication2018
AuteursHardy, D, Malvaut, S, Breton-Provencher, V, Saghatelyan, A
JournalSci Rep
Volume8
Issue1
Pagination9385
Date Published2018 Jun 20
ISSN2045-2322
Abstract

The adult mouse olfactory bulb is continuously supplied with new neurons that mostly differentiate into granule cells (GCs). Different subtypes of adult-born GCs have been identified, but their maturational profiles and their roles in bulbar network functioning and odor behavior remain elusive. It is also not known whether the same subpopulations of GCs born during early postnatal life (early-born) or during adulthood (adult-born) differ in their morpho-functional properties. Here, we show that adult-born calretinin-expressing (CR) and non-expressing (CR) GCs, as well as early-born CR GCs, display distinct inhibitory inputs but indistinguishable excitatory inputs and similar morphological characteristics. The frequencies of inhibitory post-synaptic currents were lower in early-born and adult-born CR GCs than in adult-born CR neurons. These findings were corroborated by the reduced density of gephyrin puncta on CR GCs. CR GCs displayed a higher level of activation following olfactory tasks based on odor discrimination, as determined by an immediate early gene expression analysis. Pharmacogenetic inhibition of CR GCs diminished the ability of the mice to discriminate complex odor mixtures. Altogether, our results indicate that distinct inhibitory inputs are received by adult-born CR and CR GCs, that early- and adult-born CR neurons have similar morpho-functional properties, and that CR GCs are involved in complex odor discrimination tasks.

DOI10.1038/s41598-018-27692-8
Alternate JournalSci Rep
PubMed ID29925844
PubMed Central IDPMC6010413