Biscoe TJ, Lall A, Sampson SR. Electron microscopic and electrophysiological studies on the carotid body following intracranial section of the glossopharyngeal nerve.
J Physiol 1970;
208:133-52. [PMID:
5499751 PMCID:
PMC1348776 DOI:
10.1113/jphysiol.1970.sp009110]
[Citation(s) in RCA: 75] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
1. The innervation of carotid body Type I cells has been investigated in seventeen cats. At a sterile operation the glossopharyngeal and vagus nerve roots were cut intracranially on one side.2. From 1(1/2) to 378 days after the operation the carotid bodies were fixed in situ and prepared for electron microscopy. Nerve endings on Type I cells were found to degenerate with a prolonged time course. In each cat there was a decrease in the number of nerve endings on the operated side as compared with the non-operated side.3. Before the carotid bodies were fixed, recordings were made from chemoreceptor, and baroreceptor, afferent fibres in the sinus nerve on the operated side. The chemoreceptors responded in the usual way to changes in arterial O(2), CO(2) and pH; the injection of cyanide evoked a brisk response.4. It is concluded that the nerve endings on Type I cells are efferent rather than afferent and the cell bodies of their axons are probably in the brain stem.
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