Correlation with superior cervical sympathetic ganglion and sympathetic nerve innervation of intracranial artery-electron microscopical studies.

When the superior cervical ganglion was resected in dogs, nerve degeneration in arterial walls began after about 28 h and marked degenerative substance was shown after 40-48 h; after 4 days the small cored vesicles of adrenergic axons disappeared. The same condition was seen after 3 months, but after 6 months the small cored vesicles were again visible. When the middle cerebral artery was examined by separating it into the perforating artery near to the internal carotid artery and the peripheral portion of the middle cerebral artery, degeneration of the nerve fibers of the arterial walls occurred earlier in the more proximal portion. The distribution of adrenergic nerve fibers from the superior cervical ganglion is bilateral in the anterior cerebral artery from the anterior communicating artery to the peripheral region, basilar artery, and vertebral artery, but ipsilateral only in the anterior cerebral artery as far as the anterior communicating artery, middle cerebral artery, posterior communicating artery, posterior cerebral artery and superior cerebellar artery. Degeneration of nerve fibers of the walls of these cerebral arteries was not seen ever after stellate ganglionectomy in both sides.