Dr Brian MacVicar and colleagues have uncovered how inflammation and lack of oxygen conspire to cause brain damage in conditions such as stroke and Alzheimer disease. The discovery, published in Neuron, brings researchers closer to finding potential targets to treat neurodegenerative disorders.

Chronic inflammation and hypoxia, or oxygen deficiency, are hallmarks of several brain diseases, but little was known about how they contribute to symptoms such as memory loss. The study used state-of-the-art techniques that reveal the movements of microglia, the brain’s resident immune cells. 

Brain researcher Dr MacVicar, with the Djavad Mowafaghian Centre for Brain Health at UBC and Vancouver Coastal Health Research Institute, had previously captured how microglia moved to areas of injury to repair brain damage. A video describing the findings, including microscopy footage of how microglia repair brain damage, is available at here [8].

The new study shows that the combination of inflammation and hypoxia activates microglia in a way that persistently weakens the connection between neurons. The phenomenon, known as long-term depression, has been shown to contribute to cognitive impairment in Alzheimer disease.