Biology subjects

Dejou, J.

Publications and source records attributed to Dejou, J..

2 recordsLinked to original sources

bioRxiv2026

The formation and content of odor memory from childhood

As illustrated by Marcel Prousts madeleine, childhood olfactory autobiographical memory carries a stronger positive emotional valence than memories associated with other senses. However, little is known about its content or the conditions of encoding and maintenance. Here, we asked 647 participants to freely recall and characterize their earliest childhood olfactory memory. We found that this memory is typically encoded around age six, involves pleasant odors embedded within rich multisensory contexts, and retains a strong positive emotional valence despite age-related declines in some experiential qualities. The most frequently reported scenes took place at home, in the presence of the mother, and were predominantly associated with food-related odors, although natural-vegetation odors were also commonly reported. By contrast, the non-olfactory memory is encoded earlier, visually dominated, less multisensory, less pleasant, and more frequently associated with institutional settings and friends. These findings characterize childhood olfactory memory and highlight its distinctive content among autobiographical memories.

neuroscience↗

bioRxiv2026

Engram and neural underpinning dynamics of the long-lasting childhood olfactory memory

Olfactory childhood memories are particularly important for forming ones identity. However, we dont 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 a pleasant odorant in a playful environment. In adulthood, memory recall relied on neonatal-born granule cells 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 granule cells, 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.

neuroscience↗