Effects of Na+ gradient on the intracellular Ca2+ oscillation in the sympathetic ganglion cell: Na-Ca exchange in the neurone cell soma?

The effects of the removal of extracellular Na+ and the increase in the intracellular Na+ on the slow rhythmic membrane hyperpolarizations (rmhs) were studied in bullfrog sympathetic ganglion cells. The interval of rmhs, reflecting a relative change in the basal intracellular Ca2+, was lengthened by either treatment, disfavouring the possible involvement of the Na-Ca exchange mechanism in the Ca2+-buffering in the ganglion cell soma.