Sex-, stress-, and sympathetic post-ganglionic-dependent changes in identity and proportions of immune cells in the dura

Aim of investigation: Due to compelling evidence in support of links between sex, stress, sympathetic post-ganglionic innervation, dural immune cells, and migraine, our aim was to characterize the impacts of these factors on the type and proportion of immune cells in the dura. Methods: Dural immune cells were obtained from naive or stressed adult male and female Sprague Dawley rats for flow cytometry. Rats with surgical denervation of sympathetic post-ganglionic neurons of the dura were also studied. Results: Immune cells comprise similar to 17% of all cells in the dura. These included: macrophages/granulocytes (Macs''; 63.2% of immune cells), dendritic cells (0.88%), T-cells (4.51%), natural killer T-cells (0.51%), natural killer cells (3.08%), and B-cells (20.0%). There were significantly more Macs and fewer B-and natural killer T-cells in the dura of females compared with males. Macs and dendritic cells were significantly increased by stress in males, but not females. In contrast, T-cells were significantly increased in females with a 24-hour delay following stress. Lastly, Macs, dendritic cells, and T-cells were significantly higher in sympathectomized-naive males, but not females. Conclusions: It may not only be possible, but necessary to use different strategies for the most effective treatment of migraine in men and women.