Deen M, et al. - Researchers assessed the occupancy of sumatriptan to central 5-HT1B receptors and changes in the levels of brain serotonin during migraine attacks in this study of eight patients with untreated episodic migraine without aura. Findings revealed that treatment with sumatriptan during migraine attacks seemed to be linked to a reduction in 5-HT_1B receptor binding, which is probably related to the binding of sumatriptan to central 5-HT_1B receptors, but it is not possible to exclude the contribution of ongoing cerebral serotonin release to the lower binding. The associated decline in binding from a migraine attack could signify that migraine attacks are related with endogenous serotonin increases.