Positive early-life olfactory memory is rooted in the olfactory bulb and triggers large-scale changes beyond the olfactory system

Jules Dejou, Anna Athanassi, Théo Brunel, Marc Thevenet, Anne Didier and Nathalie Mandairon

PLOS Biology, 2026, vol. 24, issue 7, 1-27

Abstract: Olfactory childhood memories are particularly important for forming one’s identity. However, we don’t know how they exert their privileged influence and shape brain structure. To address this, we modeled childhood olfactory memory in mice based on a human survey indicating that our earliest olfactory memory arises from repeated positive experiences paired with a pleasant odorant. Accordingly, mice were exposed during childhood to an attractive odorant in a playful environment. In adulthood, memory recall relied on neonatal-born granule cells (GCs) in the olfactory bulb, as their optogenetic silencing impaired retrieval, and on increased functional connectivity in the reward system. With age, memory persistence depended on re-exposure to the childhood odorant and was associated with the disengagement of neonatal-born GCs, alongside with strengthened limbic functional connectivity. Together, these findings identify neonatal neurons as a key substrate for encoding childhood olfactory memory and reveal dynamic reorganization of brain networks supporting its long-term significance.How do olfactory early-life memories exert their privileged influence on long-term memory and shape brain structure? This study uses a survey in humans and experiments in mice to show that early experiences with pleasant odorants create persistent memories supported by neonatal neurons and dynamic brain connectivity, uncovering how childhood sensory experiences retain lifelong emotional significance.

Date: 2026
References: Add references at CitEc
Citations:

Downloads: (external link)
https://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.3003845 (text/html)
https://journals.plos.org/plosbiology/article/file ... 03845&type=printable (application/pdf)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:plo:pbio00:3003845

DOI: 10.1371/journal.pbio.3003845

Access Statistics for this article

More articles in PLOS Biology from Public Library of Science
Bibliographic data for series maintained by plosbiology ().