Protect the Barrier

Ruthless, deadly and supposed to be on our side – battling immune cells often leave infected tissues swollen and inflamed, threatening delicate organs like the brain. Fortunately we have a protective layer, the blood–brain barrier, which usually shields our delicate neurons – yet sometimes hordes of immune cells break through. Here scientists investigate a similar invasion in developing Drosophila [fruit fly] brains, finding macrophages (highlighted in purple) push through the barrier aided by the brain’s supportive glial cells (green). Once inside, the immune cells spread quickly (right), interfering with neurons (turquoise) and their connections, called synapses. Living models like Drosophila allow researchers to ponder how the human blood-brain barrier might be strengthened, and how they might calm the immune response, using drugs to strike a healthy balance between defence and destruction.

Written by John Ankers

John Ankers

Writer

A former researcher in systems biology, John is now an online biology tutor and professional coach supporting the wellbeing of scientists and NHS professionals. He's writing, too, of course.

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• Image adapted from work by Bente Winkler and colleagues
• Institut für Neuro- und Verhaltensbiologie, Universität Münster, Münster, Germany
• Image originally published with a Creative Commons Attribution 4.0 International (CC BY-NC 4.0)
• Published in Science Advances, October 2021