Effects Of Trigeminal Ganglion Electrical Stimulation On The Positive Neurons Of Nitric Oxide Synthase And Vasoactive Intestinal Polypeptide In Sphenopalatine Ganglion And Dura Mater

Objective:The objective of this research were to observe expression level of nitric oxide synthase (NOS)and vasoactive intestinal polypeptide(VIP)in sphenopalatine ganglion and dura mater in migraine model of rat and to investigate the role of parasympathetic nerve during migraine attacks.Methods:16 male SD rats,weighing 220-250g,were divided randomly into the experimental group and the sham group,(each group:n= 8 ). The rats were drilled on their cranium by platform bur. The electrode was inserted vertically into the right trigeminal ganglion, through a hole bored on the skull 3 mm posteriorly from the bregma and 3mm laterally. Depth of the tip of the stimulating electrode was about 9.5 mm from the dural surface.The experimental group was termed as migraine model and the rats were treated by electrical stimulating trigeminal ganglion, while the rats of sham group were only operation without electrical stimulating. The right trigeminal ganglion was electrically stimulated (200 ms ,10 V, 5ms) for 30 min.(1) The expression level of NOS and VIP was detected in sphenopalatine ganglion in a rat model of migraine using histochemical and immunoflurescence staining methods respectively.(2) The expression level of NOS and VIP was detected in dura mater using immunoflurescence staining methods.Results:(1)The number of NOS-positive neurons and VIP-positive neurons was respectively increased more significantly(P < 0.01)in sphenopalatine ganglion in experimental group than that in sham group.(2) NOS and VIP in dura mater was localized.Conclusion:The trigeminal–autonomic reflex may be active by trigeminal ganglion electrical stimulation,which then significantly increased the activity of the neurons of NOS and VIP in sphenopalatine ganglion. Violent dilation of meningeal vessels and intracranial large vessels maybe involved in the increased numbers of both NOS and VIP positive neurons in sphenopalatine ganglion and dura mater in pathogenesis of migraine.