An experimental model of migraine with aura: Cortical hypoperfusion following spreading depression in the awake and freely moving rat

1. Cortical spreading depression (CSD) was induced by direct current stimulation of the lateral frontal cortex in awake and freely moving rats. 2. Regional cerebral blood flow (rCBF) was continuously measured by a laser Doppler flowmeter using an acrylic cup which was chronically fixed on the surface of the cerebral cortex. Under the resting condition rCBF remained constant throughout the observation period and showed a high reproducibility. 3. rCBF increased to approximately 190% of control values during 1-3 min after CSD, and decreased to approximately 80% of control values, before returning to normal values 60 min after CSD. 4. These results are consistent with those found in anesthetized animals. This is the first study which has continuously monitored cortical hypoperfusion after CSD in awake and freely moving rats. The model is a useful system for studying migraine with aura.