Neuromuscular contacts in intracranial arteries of the cat.

Nerves of intracranital arteries of the cat were restricted to adventitia, with neuromuscular contacts observed only at the border of adventitia and media. Axons of such neuromuscular contacts possessed at least two different populations of synaptic vesicles. One axonal type contained manzy small (500 angstroms in diameter) granular vesicles and occasional agranular vesicles. The other contained only agranular vesicles.