Cerebrovascular application of bradykinin excites central sensory neurons.

The activity of sensory neurons in the trigeminal brainstem complex and thalamus responsive to electrical stimulation of the cerebrovasculature was monitored during topical application of bradykinin to the cerebral vessels or during an intravascular injection of bradykinin into the sagittal sinus. Bradykinin was found to excite 8 of the 15 cells studied. The excited cells were usually those that were spontaneously active and received nociceptive input from the oro-facial region. These neurons may be involved in mediating vascular head pain related to the acute or pathological changes of the cerebral vessels and/or the associated trigeminovascular sensory afferents.