Researchers have pinpointed a brain stress signal that may spark migraine pain.

Migraines are thought to be caused by a wave of cellular depolarization that travels through the brain's cortex. Turgay Dalkara and his colleagues at the Hacettepe University in Ankara induced depolarizing waves in the exposed brains of mice by pricking the cortex with a pin or by applying potassium chloride to it.

The authors then used molecular and pharmacological tools to document the cascade of molecular events that led to activation of the trigeminal nerves, which innervate the face and are implicated in migraines.

Science 339, 1092–1095 (2013)