 To investigate interictal opioid receptor MOR binding potential BPND changes in migraineurs as compared to agegender-matched healthy controls. To demonstrate that frequency of the headache attacks and severity of cutaneous allodynia levels in migraineurs experienced over multiple attacks are correlated with levels of MOR BPND in specific brain regions. To investigate whether dysfunction of the pain regulatory endogenous opioid system of migraineurs is correlated with changes in the gray matter thickness in cortical areas associated with pain perception and modulation. 