Fig. 1

5-HT reactivity in the hand vein expressed in venoconstriction units (VCU). Significant differences were found in the 5-HT doses eliciting roughly the same amount of contraction: migraine patients (examined in headache-free period) are more sensible (lower 5-HT dose) than controls (P < 0.001), migraine women are more sensible than migraine men (P < 0.001). Data from Panconesi et al. [37]