Illustration: Michael Helfenbein

In most of the world, winter long ground to a halt to make way for more harmonious seasons. Still, these are still tense times for your health, as one day can be sunny, the other murky and cold. A lot of people get snuffed and catch a cold. While you’re tucked inside your sheets, blowing your nose and cursing the day you caught that wretched cold, comfort yourself with the thought at least it wasn’t your brain that caught the cold.

I know what you must be thinking; what kind of comforting thought is that? A new study by Yale School of Medicine researchers, which appeared in the  Journal of Virology, shows that when a virus is detected in the nose a long-distance signaling system can activate anti-viral defenses in distant parts of the brain.

“When you think about it, it is more crucial to health of the brain more than any other organ to have robust mechanisms to combat viruses,” said Anthony van den Pol, professor of neurosurgery and lead author of the study. “Brain cells don’t turn over. Once they are dead they are dead.”

The Yale researchers note that  most signals in the brain travel about 20 nanometers across a synapse but when the olfactory bulb detects a viral invader immune system defenses are activated nearly a million times farther away even in uninfected areas of the brain. Research conducted in mice also shows this response is independent of the peripheral immune system.