Figure 5.

Effects of ligustrazine on nociceptive trigeminovascular activation. Time course changes in (a) ongoing spontaneous trigeminal neuronal firing and (b) the average response of intracranial dural-evoked Aδ-fiber trigeminal neurons to intravenous administration of saline and ligustrazine (3 and 10 mg/kg). Ligustrazine had no effect on ongoing spontaneous trigeminal neuronal firing, but caused a dose-dependent inhibition of intracranial dural-evoked Aδ-fiber trigeminal firing. Only ligustrazine (10 mg/kg) caused inhibition of intracranial dural-evoked Aδ-fiber trigeminal firing, after 75–90 min. Data are represented as mean ± SEM **p < 0.01 compared with an average of the four baselines, using Student’s paired t test.