[Central noradrenergic regulation of cerebral blood flow]

In acute experiments in anesthetized cats after upper cervical sympathectomy, the influence of locus coeruleus stimulation on carotid blood supply of the brain and the local cerebral blood flow (CBF) in the parietal region were studied. The stimulation increased both the arterial pressure and the local cortical blood flow. If the arterial pressure was stabilized with pressostate, the stimulation decreased the cerebral blood supply and increased the local CBF after a 2-sec latency. This suggests that the intracerebral noradrenergic system performs the direct neurogenic control of cerebrovascular tone. The influence of this system differs in different regions of the cerebral vascular bed.