Conférenciers
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Alexandra Castillo-Ruiz, PhD Assistant Professor
Department of Psychology and Neuroscience Program, Michigan State University, East Lansing, USA
At birth, the newborn leaves the safety of the womb to experience a milieu of extraordinary events, including mechanical pressure, hypoxia, and microbial colonization from maternal and environmental sources. Under any other circumstance in life these events would affect brain function. However, it is unknown whether and how birth affects the developing brain. To address this, I have taken two approaches using mice. In the first, I varied microbial exposure at birth and found altered patterns of cell death (a key feature of brain development) and colonization of the brain by microglia (the resident immune cells of the brain), as well as altered brain expression of important immune system molecules. In more recent work, I discovered that the maternal microbiota may program some of these effects already in the womb via bacterial metabolites. In a second approach, I varied birth mode: i.e., vaginal vs C-section (which bypasses maternal and offspring signals associated with birth), and found that C-section birth also alters patterns of cell death across the brain in offspring. Moreover, I found that this effect is associated with fewer and smaller vasopressin neurons in adult C-section born mice, suggesting that birth mode, perhaps via cell death mechanisms, has long-lasting effects on brain development. Interestingly, behaviors linked to the vasopressin system (neonatal ultrasonic calls) were also altered in C-section born animals, suggesting that the effects of C-section birth are meaningful for behavioral development. It is possible that differences in microbiota colonization between birth modes (as shown by others) could cause these effects. Future work will address this possibility. Since humans around the world now routinely engage in practices that alter the natural birthing experience (e.g., antibiotic usage, C-sections) this work has obvious clinical implications.
Bâtiment: Duclaux
Salle: Duclaux amphitheater
Adresse: 25-28 Rue du Docteur Roux, Paris, France