White blood cells could play a role in brain development and the onset of neurodevelopmental disorders

Four per cent of Canadian children between the age of five and fourteen live with a neurodevelopmental disorder. While the underlying biological mechanisms generally remain unknown, Micaël Carrier (Neuroscience Graduate Program, PhD candidate, Tremblay Lab) thinks the brain’s immune system may have something to do with it.

Micaël is researching how white blood cells influence the maturing brain and whether they are involved in the onset of neurodevelopmental disorders. He recently received a doctoral training grant worth $21,000 a year for 3.5 years from the Fonds de recherche du Québec – Santé (FRQS) to fund his work.

There is a growing evidence indicating that environmental risk factors like pollution, stress, infection, and diet compromise the immune system, which is a key component in the development of neurodevelopmental disorders. Upon exposure to environmental risk factors, white blood cells—a type of immune cell that, unlike microglia, does not normally reside in the brain—can enter the brain and contribute to the immune response.

“In this project, I will start from my discovery that white blood cells invade the developing brain to study how they influence its maturation,” Micaël says. “These findings will provide insights into how these cells may be involved in the onset of neurodevelopmental disorders. I will use a combination of cutting-edge microscopy techniques to shed light on the role of these white blood cells during development.”

Micaël says his project will lead to a better understanding of normal brain development. This is significant because this mechanism, previously completely unknown, could be critically linked to the cause of neurodevelopmental disorders. His work will also pave the way for the design of novel therapeutic approaches involving reprogramed white blood cells to treat neurodevelopmental disorders, improving their beneficial function during pathology and thus helping to improve lives of young Canadians afflicted by these conditions.

Micaël’s application for his doctoral training grant was ranked first in the category.