The Brain’s Life Story

"In Strasbourg, there is a research facility where macaques live in large outdoor parkland enclosures. They forage, form alliances, squabble over social rank, and generally get on with the business of being monkeys. They also, as part of a long-running study, sit down at touchscreens and complete attention tasks. Thirty-two individuals were tested repeatedly across several years.
Most of them behaved. Attention and impulse control followed predictable arcs across the lifespan, clear phenotypes emerged, and the data told a coherent story about how attention and impulsivity shift across a lifetime.
And then there was Olga. Across every time point and every year of testing, she remained one of the most impulsive individuals in the group. This talk is about what these monkeys taught us, and about one who never learned to wait."

Why do similar life experiences leave some people resilient, while pushing others toward psychiatric illness? In this talk, we will explore how the roots of resilience and vulnerability may begin much earlier than we think, shaped by experiences across early life that leave lasting marks on both the brain and the body. Far from being fixed traits, resilience and susceptibility emerge from a complex biological dialogue between development, stress, and the immune system. By uncovering how early adversity can influence behavior, mental health, and lifelong responses to stress, this work invites us to rethink psychiatric disorders not simply as conditions that appear in adulthood, but as outcomes of a much longer story—one written from the very beginning of life.

Dans le cerveau, de petites cellules appelées microglies agissent comme des gardiennes, contribuant à façonner et à protéger les connexions neuronales dès le début de la vie. Elles éliminent les débris, affinent la communication entre les cellules nerveuses et réagissent aux changements de leur environnement local. Mais si ces cellules ne fonctionnent pas correctement dès les premières étapes du développement du cerveau, leurs actions peuvent avoir des effets durables et accroître la vulnérabilité aux dommages au fil du temps. Cela peut contribuer à des pathologies cérébrales comme la maladie d’Alzheimer ou la sclérose latérale amyotrophique. Sur le plan mécanistique, des variations de certains gènes dans les microglies peuvent augmenter le risque de développer ces maladies. Comprendre comment ces gènes influencent la formation du cerveau pourrait ouvrir de nouvelles pistes pour prévenir ou ralentir la maladie bien avant l’apparition des symptômes.