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Electron microscopic and electrophysiological studies on the carotid body following intracranial section of the glossopharyngeal nerve
Author(s) -
Biscoe T. J.,
Lall A.,
Sampson S. R.
Publication year - 1970
Publication title -
the journal of physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.802
H-Index - 240
eISSN - 1469-7793
pISSN - 0022-3751
DOI - 10.1113/jphysiol.1970.sp009110
Subject(s) - carotid body , glossopharyngeal nerve , efferent , carotid sinus , efferent nerve , chemoreceptor , vagus nerve , anatomy , electrophysiology , free nerve ending , baroreceptor , afferent , chemistry , cats , medicine , anesthesia , heart rate , stimulation , reflex , blood pressure , receptor
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 1½ 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.