Anatomical mapping of the cerebral nervi vasorum in the human brain.

The authors present an anatomical study of the vascular nerve fiber distribution to the human intracranial arteries. These fibers are abundant in the circle of Willis and its neighboring arteries, but there are no vascular nerves in small pial arteries over the convexity. These nerve fibers are provided with a cluster of synaptic vesicles as they approach the smooth muscle cells of the media. Adrenergic axons are also found in these fibers.