Cervical sympathectomy reduces neurogenic vasodilation in dura mater of rats

Migraine may affect the autonomic nervous system, but the mechanisms remain unclear. The sympathetic and parasympathetic nervous systems may play different roles in the attack. To explore the effect of blocking the cervical sympathetic nerve on vasodilation of the meningeal vessels, jugular vein calcitonin gene-related peptide (CGRP) and meningeal blood flow changes were measured before and after transection of the cervical sympathetic nerve by electrically stimulating the trigeminal ganglion in Sprague-Dawley (SD) rats. We found that CGRP level and meningeal blood flow increased in both the sham-operated and sympathectomized groups (p < 0.05). Compared with the sham-operated group, dural blood flow decreased significantly in the cervical sympathectomy group, but CGRP level was not significantly different between these two groups. The cervical sympathetic nerve may play an important role in the process of neurogenic dural vasodilation in rats; this effect is not entirely dependent on CGRP level.