The Preparation And Evaluation Of Experimental Animal Model As Iterative Attacks Of Migraine

Objection:To build a reliable experimental animal model that can mimic the iterative migraine attacks and can be used in the basic research on the mechanism, therapeutical drugs and other approaches of vascular headaches such as migraine.Methods:12 cats weighted 2.0⁴.0Kg were randomly divided into three groups: sham-operation, acute stimulation and iterative stimulation groups. The cats were anesthetized with 846 mistura (0.1 ml/kg, i.m.), and then two stainless steel guide tubes (1.5mm in diameter, 10mm in length) were mounted over holes drilled through skull overlying the SSS and were cemented using dental acrylic cement. The dura mater along with SSS of cats in the acute stimulation group was electrically stimulated with square wave current (250μs, 1.5mA, 3 Hz) for 2 hours on the 8th day after the operation. The iterative stimulation group was stimulated for 2 hours a day for 8 days, No cat was stimulated in the sham-operation group. 1 hour after stimulation, cats were paralyzed and perfused to fix, which the brainstem and the superior cervical spinal cord were removed and post-fixed. The expression of c-fos and nNOS immuno-reactivities was detected with immunohistochemical method.Result:The c-fos and nNOS immunoreactive positive neurons were observed in laminae â…  and â…¡ of the trigeminal nucleus caudalis, the dorsal horn of the C₁ and C₂ segment of the cervical cord, the nucleus of the solitary tract and the laminae X of the upper cervical cord. The number of c-fos and nNOS immunoreactive positive neurons increased markedly in the stimulation groups comparing with the corresponding sham-operation group. There was no much difference about the number of c-fos and nNOS immunoreactive neurons in between acute stimulated group and iterative stimulated group.Conclusion:The second-order neurons of trigeminal nerve which those are related to the transmission of nociception involved in migraine could be activated by stimulation of dura mater near the SSS. Whether iterative stimulations can increase the excitability of the second-order neurons of trigeminal nerve is still unclear. The model which dura mater near the SSS of cats was repeatedly stimulated could be trustworthily used to study on the pathophysiology, and to develop the prophylactic and therapeutical drugs and other approaches of vascular headaches such as migraine.