Migraines Degrade Brain Wiring in Mice

Migraines, affecting some 28 million Americans, may degrade the synapses that keep our brains connected.

By combining two recently developed imaging technologies, Nedergaard’s team was able to get an unprecedented look at the events that happen in the brain of a mouse as a migraine unfolds. The team uncovered a complex, unexpected tale of supply and demand regarding blood flow and oxygen.

In short, the team found that the brain develops a voracious demand for energy as the organ attempts to restore the delicate chemical balance that is lost in the initial throes of a phenomenon known as cortical spreading depression [CSD], which is thought to underlie many migraines. [...]

Nedergaard's team linked the phenomenon for the first time to both severe hypoxia and to damage to brain cells. As a result of CSD, the team found changes to the synapses, the connections between brain cells known as neurons. The team observed that nerve cells swell and begin to disintegrate, with neurons shedding important connections known as dendritic spines -- the tiny extensions of an individual neuron's body that usually number in the thousands within a synapse. Mice in the grasp of a migraine lost up to three-quarters of these important cellular components.

Arteries in the brains of mice suffering from migraines expand to increase blood flow to the affected areas, but Nedergaard observed that pockets of oxygen deprivation persisted in areas further away from the arteries. This deprivation, or hypoxia, caused too great a demand for oxygen for the body to keep up.

Whether or not the damage is permanent remains unknown, according to an MSNBC report.

A recent study in mice showed that an enriched environment encourages synaptic remodeling, so exercise may be beneficial if the results are permanent. Although some reports suggest that exercise can trigger migraines, The Migraine Trust -- a UK-based charity for migraine research -- provides a fact sheet offering (.pdf) ways on using exercise to manage migraines.

Mice with a Migraine Show Signs of Brain Damage [University of Rochester Medical Center]