Adrenergic innervation of the vasa nervorum in the cranial nerves and spinal roots in the subarachnoid space.

Fluorescence microscopy revealed that the innervation of the vasa nervorum of both cranial and spinal nerve roots in the subarachnoid space in the monkey is adrenergic in nature. The endoneurium of the cranial nerve roots contained free adrenergic nerve fibers which were not related to the vessel wall.