Acetylcholinesterase Activity in the Perivascular Nerve Plexus of the Basilar and Labyrinthine Arteries

Abstract

Acetylcholinesterase (AChE) activity was demonstrated in the perivascular nerve plexus of the cat basilar and labyrinthine arteries, using a histochemical technique. The basilar artery was found to be surrounded by dense AChE-active nerve bundles and fibers. The periarterial nerve networks were observed to continue on the anterior inferior cerebellar and labyrinthine arteries, but, under the light microscope, none of the AChE-positive nerve fibers were seen on the peripheral cochlear and vestibular arteries. Though the vascular wall of the vessels in the stria vascularis and spiral ligament showed AChE activity, neural structures were not discerned. Since the perivascular innervation with AChE-positive nerve fibers was detected only up to the labyrinthine and common cochlear arteries, the neurogenic control of the blood vessels in the inner ear is possibly not directly exerted in arteries of the labyrinth.