Skip navigation
Guardians of the Brain
Article

Guardians of the Brain

The brain’s borders teem with an army of immune cells that monitor and protect it.

Nature, 2022


Editorial Rating

8

Qualities

  • Scientific
  • Eye Opening
  • Overview

Recommendation

The blood-brain barrier functions as an extra protective layer to protect the brain from any potentially damaging agents in the rest of the body. It is such a strong barrier, though, that most researchers thought it separated the brain from the body’s immune system as well. But, as Diana Kwon reports in Nature, new work suggests that this separation is not as absolute as once thought. Immune cells are found in the membranes surrounding the brain, and they can send molecular signals into the nerve cells within.

Summary

Many types of immune cells cannot cross the blood-brain barrier, but others patrol the borders and can send in signaling molecules.

The blood-brain barrier protects brains from pathogens and any other potentially harmful agents that aren’t supposed to be there. It also separates the brain from much of the mundane goings-on in the rest of the body – including, it had long been assumed, the immune system. But research conducted over the past 10 years or so overturns that assumption, indicating that immune cells surround the brain and communicate with neurons.

The brain has its own special immune cells, called microglia. Most researchers thought that this was the extent of the interaction between the brain and the immune system. But in 1999, Michal Schwartz...

About the Author

Diana Kwon is a freelance science journalist based in Berlin. She covers the life sciences, health and academic life. Her work has appeared in publications such as Scientific American, The Scientist, Nature and Quanta.


Comment on this summary

More on this topic

Learners who read this summary also read