Vasomotor nerves of vessels in the human optic nerve.

Aminergic and cholinergic vasomotor nerves in vessels of the human optic nerve were studied morphologically. Aminergic nerve fibers were observed by the glyoxylic acid method. Cholinergic nerve fibers were observed by light microscopy after acetylcholinesterase staining by the Karnovsky-Roots method and Tago's modified method. In the retrobulbar optic nerve behind the bulbus, aminergic and cholinergic vasomotor nerves were observed to be dense in the central retinal artery and vein and posterior ciliary arteries. A large number of vasomotor nerves were also demonstrated in vessels in the septum of the optic nerve, but they were sparse in pial vessels. Further centrally, a few vasomotor nerves were found in pial vessels of the intracanalicular and intracranial optic nerve, but few were observed in the septum of the optic nerve. At the optic chiasm they were densely distributed in pial vessels.