Effects of denervation on the glomus cell membrane

Trophic influences of the carotid nerve (CN) on carotid body (CB) glomus cells were studied by comparing the membrane potential (Em), input resistance (Ro) and voltage noise (Erms) of normal and 3-31-day denervated cells had more negative Ems. Higher Ros were recorded at 3 and 6 days. Erms sharply increased at 3 days, returned to normal at 6-15 days and was below normal at 31 days. A transmitter (ACh) and NaCN, producing histotoxic anoxia, were used for stimulation. These substances either depolarized or hyperpolarized innervated cells and increased or decreased voltage noise. Denervation selectively changed these patterns but only for a short time. ACh preferentially depolarized the cells, only at 3 days, whereas its effects on noise did not change. The Em responses to NaCN remained unaltered although at 3-6 days noise increases were smaller and depressions exaggerated. Possible reasons for these effects are discussed.