How Aura May Trigger Migraine Pain

Migraine headaches can last for days. Some people have what’s called an aura before migraine pain sets in. Aura can include visual disturbances, such as seeing flashing lights. And it can include other sensory changes, like numbness or tingling.

Scientists have known that aura is caused by a disruption of electrical activity within the brain. But they hadn’t yet figured out how the aura might trigger pain. The nerve cells that drive migraine pain are known to sit outside the brain. And communication between these nerves and the brain was thought to be blocked by a structure called the blood-brain barrier.

To learn more, researchers looked at how spinal fluid flows out of the brains of mice. They found gaps in the blood-brain barrier around a bundle of nerve cells known to process migraine pain. Substances injected directly into the brain flowed into these nerve cells within half an hour. This time period is similar to the typical time between aura and headache.

The scientists next provoked migraine aura in the brains of mice. Then they measured changes in proteins that flowed into the nerve cells. They found changes in many proteins known to be involved in migraine headache. The results point to potential new ways to relieve migraine pain.

“These findings provide us with a host of new targets to prevent and treat migraines and strengthen existing therapies,” says Dr. Maiken Nedergaard of the University of Rochester, who helped lead the study.