Our understanding of the pathophysiological mechanisms of migraine remains poor despite the availability of clinically effective drugs and many years of research. Historically, two independent theories regarding the aetiology of headache were suggested: vascular and neuronal. However, recent data demonstrate that neuronal excitation modulates both the pial and meningeal circulation through a critical interaction with the trigeminal nerve, supporting the concept that the integration of neuronal and vascular information in the trigeminovascular network represents a key event in the aetiology of migraine.