Proust's madeleine explained by neuroscience

Described by Marcel Proust as early as 1913, the phenomenon by which certain smells revive vivid and generally pleasant childhood memories is thought to originate in neurons of the olfactory bulb. By exposing mice to pleasant smells in playful environments, a CNRS team has succeeded in identifying these particular neurons, which form during early childhood and persist over time, unlike other neurons that are frequently renewed. They are closely linked to the orbitofrontal cortex, the olfactory tubercle, and the lateral entorhinal cortex—regions involved in emotional regulation, memory, and reward. Moreover, with age and the reorganization of neural networks, the connectivity of these olfactory bulb neurons strengthens within emotional circuits. This is why, once reactivated in adulthood by the associated smell, the stimulation of these neurons is associated with a strong emotional charge linked to childhood memories.