Tremblay contributes electron microscopy work to study published in Nature Communications

Dr. Marie-Éve Tremblay, Canada Research Chair (Tier II) in Neurobiology of Aging and Cognition and Associate Professor at the Division of Medical Sciences, contributed to a breakthrough paper published in Nature Communications on Monday.

Tremblay and her colleagues found that omega-3 deficiency can negatively affect a developing brain. It does so by changing the activity of the brain’s immune cells, called microglia. During normal development, these microglia “sculpt” neural networks by “eating” unnecessary connections between neurons (i.e., synapses) and retaining those that are essential for proper brain function. However, when there is an omega-3 deficiency, the immune cells lose their ability to recognize which synapses need to be removed. As a result, they eat too many connections. This creates a poorly formed neural network, which affects the infant’s memory.

To study the link between omega-3 intake and brain development, the researchers developed various technologies to assess changes in microglia behaviour towards synapses, analyze their lipid content, test the different molecules to identify those responsible for the dysfunction, and find out how to restore this function.

Tremblay and members of her lab, Cynthia Lecours and Kanchan Bisht, conducted electron microscopy experiments to show microglia engulfing synapses at nanoscale resolution.

This study could lead to modifying nutritional guidelines for pregnant and breastfeeding women to increase their recommended intake of omega-3 to prevent neurodevelopmental disorders in infants.

The study was led by researchers at Bordeaux University, in collaboration with colleagues in Canada, France, Italy, Spain, and the US.

At the DMSC, Tremblay and her lab continue to explore the significance of microglial remodelling of neuronal circuits and elimination of synapses in the pathogenesis of brain disorders. They are using state-of-the-art technologies to identify unique microglial functions that contribute to learning and memory, stress resilience, and overall adaptation to our world in constant evolution.