In his early carrier he identified the cortical mechanism that underlie migraine in patients as a cortical spreading depolarization wave, and he showed that the same mechanism contribute importantly to brain pathology in acute brain injuries. Now, using mouse models he has revealed new elements of the regulation of brain vascular responses to stimulation, and key mechanisms that guide vascular cells to direct oxygen and glucose to active nerve cells. Lauritzen has discovered that specific parts of small blood vessels control the trafficking of substances from blood and brain and that signalling molecules in the blood contribute to vascular barrier properties. His studies unravel pathophysiological mechanisms in acute brain disorders, and communication pathways between nerve networks and blood vessels needed to control brain energy supply in health and disease.