Multi-Unit Compartmentation of the Carotid Body Chemoreceptor by Perineurial Cell Sheaths: Immunohistochemistry and Freeze-Fracture Study

The existence and extent of the perineurial cell envelope in the carotid body was clearly demonstrated by the immunoreactivity for nerve growth factor receptor (NGFR) and the freeze-fracture analysis. Consequently the chemoreceptor is regarded as multiple units, each of which consists of certain numbers of chief and sustentacular cells and nerves covered as a whole by a sheath of the perineurial cells.