Chronically denervated rat carotid bodies

Abstract

The ninth nerve was severed and the rat carotid body studied in the light and electron microscopes and after formaldehyde-induced fluorescence for its catecholamine content from 3 weeks to 13 months after operation. Minimal changes in the carotid body were observed. Hyperthrophy of the capsule cell was noticed up to about 2 months, after which time these cells appeared normal. Lysosomes in the capsule cells occurred more frequently and were larger than in normal carotid bodies. Discernible pathological alterations did not occur in the glomus cells, despite the absence of afferent terminals upon them. Atrophy of the carotid body was not noticed. The catecholamine content of the denervated carotid body was comparable to its innervated control and no nerve terminals were found on the glomus cells. Autonomic ganglion cells intrinsic to the carotid body varied in number from 1 to 8 and in location. The glomus cells do not receive any significant autonomic innervation, and the ganglion cells in the carotid body, perhaps sympathetic, probably innervate blood vessels. It is concluded that deafferentation has minimal morphological effects on the carotid body. The reactions of other receptor cells to deafferentation are compared with those of the glomus cells.

An Ultrastructural Study of Nerve Cell Bodies in the Carotid Body and Common Carotid Artery of the Domestic Fowl

“…The occurrence of nerve cell bodies within the carotid body and carotid baroreceptor zone of the domestic fowl has not been reported, but the presence of occasional neurons in the vicinity of the carotid body have been briefly noted by BENNETT (1970) and DREYER, DE BOOM, WET, HUGO and ELOFF (1978). In mammals, on the other hand, nerve cell bodies have been reported in the carotid body (BISCOE and STEHBENS, 1966; MCDONALD and MITCHELL, 1975;KONDO, 1976;HESS, 1977) but, they have not been reported within the arter,bl wall of the carotid sinus region. It is recalled here that the carotid baroreceptor zone in-the domestic fowl is the homologue of the carotid sinus of mammals (ABDEL MAGIED, TAHA .…”