Killam Seminar Series: Microglial (ultrastructural) diversity in health, aging and neurodegenerative disease

Tuesday, May 23, 2023 16:00to17:00
Virtual / online

To attend in person, register here.

To watch via vimeo, click here.

Marie-Eve Tremblay

Associate Professor, Medical Sciences, University of Victoria, Canada

Host: Edward Ruthazer

Bio: I have received my PhD in Sciences neurologiques at Université de Montréal, Canada in 2009. I was a Postdoctoral Fellow in the Department of Neurobiology and Anatomy and Center for Visual Science at the University of Rochester, United States from 2009 to 2011 and in the Department of Psychiatry at the University of Wisconsin- Madison, United States from 2011 to 2012. I was then recruited as an Assistant Professor in the Department of Molecular Medicine at the Université Laval, Canada in 2013, awarded a Tier II Canada Research Chair in Neuroimmune Plasticity in Health and Therapy in 2017, and promoted to the rank of Associate Professor with tenure in 2018. I subsequently accepted an Associate Professor position at the Division of Medical Sciences, University of Victoria, Canada with a Tier II Canada Research Chair in Neurobiology of Aging and Cognition in 2020.

Abstract: Microglia recently emerged as highly diverse cells comprising several structural and functional states, indicating a critical involvement in orchestrating brain development, plasticity, behavior, and cognition. Various environmental factors, combined with individual genetic predispositions, confer an increased risk for neurodevelopmental and neuropsychiatric disorders, as well as neurodegenerative diseases. Microglia are highly sensitive to chronic stress, inadequate diets, viral/bacterial infections, pollution, and insufficient or altered sleep, especially during critical developmental periods, but also across life. These environmental challenges can compromise microglial physiological functions, notably resulting in defective neuronal circuit wiring, altered brain functional connectivity, and the onset of behavioral deficits into adolescence, adulthood, and aging. In my talk, I will discuss how environmental challenges can affect microglial structure and functions, and increase their ultrastructural diversity. Among the discoveries, our work has identified the dark microglia which are abundant during embryonic and postnatal development, then become rare during young adulthood. Dark microglia present several markers of cellular stress and metabolic alteration, as well as increase in number up to 10-fold with the exposure to environmental risk factors and disease pathology. These cells display excessive interactions with synapses, the vasculature and myelinated axons, suggesting a key role in brain circuit remodeling across development, stress-induced plasticity and disease.



Supported by the generosity of the Killam Trusts, the MNI's Killam Seminar Series invites outstanding guest speakers whose research is of interest to the scientific community at the MNI and McGill University.

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The Neuro (Montreal Neurological Institute-Hospital) is a bilingual academic healthcare institution. We are a McGill research and teaching institute; delivering high-quality patient care, as part of the Neuroscience Mission of the McGill University Health Centre. We are proud to be a Killam Institution, supported by the Killam Trusts.



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