Nociceptive behaviors were induced by electrical stimulation of the dura mater surrounding the superior sagittal sinus in conscious adult rats and reduced by morphine and rizatriptan benzoate

Abstract

The trigeminovascular nociception induced by electrical stimulation of the dura mater surrounding the superior sagittal sinus in anesthetized animals has been widely used as a model for investigation of the pathophysiology of vascular headache such as migraine. However, little is known whether pain behaviors can be induced using this model in conscious animals. Thus, to establish a new model of trigeminovascular nociception in conscious animals and to examine the effects of morphine and rizatriptan benzoate on nociceptive behaviors in this new model, we electrically stimulated the dura mater surrounding the superior sagittal sinus. We found that grooming and head-flick activities were altered partially in a frequency-dependent way and that frequencies ranging from 10 to 20 Hz more easily provoked these behaviors. Moreover, we also demonstrated that these behaviors were reduced by morphine and rizatriptan benzoate. Thus, this new model will provide a useful and appropriate tool to directly assess changes in the intensity of pain for further investigation of pathophysiological mechanisms of migraine in conscious animals.