Trophic effects of axonal elements upon the type 1 cells of the carotid body of the domestic fowl.

The carotid body Type 1 cells of twelve adult domestic fowls were examined with the electron microscope either 5-15 days after distal vagal ganglionectomy (3 birds) or from 5 to 462 days after midcervical vagotomy (9 birds). An increase in the number and size of Type 1 cell granular vesicles was noted after deafferentation by ganglionectomy. In vagotomised birds, degeneration and regeneration of the axonal elements of the carotid body were respectively accompanied by degeneration and then reappearance of the Type 1 cells. It was concluded that axonal elements of the carotid body exert a trophic influence on the Type 1 cells.