Arterial supply of the rat superior cervical ganglion: a morphological and semiquantitative histochemical investigation.

A combination of morphological and semiquantitative techniques has been employed to characterise the arterial supply to the rat superior cervical ganglion. Microfil and ink-injected preparations indicate that the major supply is from the carotid body artery which sends several branches to the rostral part of the ganglion and a recurrent branch to its caudal part. Occlusion of the proximal part of the external carotid artery, and hence the carotid body artery (whether it be derived from the external carotid or occipital artery), produces a dramatic reduction in neuronal succinate dehydrogenase activity within 30 minutes. In contrast, section of the preganglionic trunk and vagus nerves--whose vascular beds are seen to anastomose with that of the superior cervical ganglion--results in no observable change in ganglion activity. It is concluded that the carotid body artery is the only significant artery of supply to the rat superior cervical ganglion and therefore that preganglionic neurectomies can be carried out without risk of anoxia to the neurons of the ganglion.