Fig. 2From: Serotonin and migraine: a reconsideration of the central theorySeasonal variations of 5-HT hand vein contraction, expressed in venoconstriction units (VCU), in a group of 261 migraine patients. In the summer higher 5-HT doses provoke a lesser amount of venoconstriction. From Panconesi et al. [37], modifiedBack to article page