Study of cell regulation by sodium sensor channels

点击翻译按钮获取中文摘要

Sodium homeostasis is crucial for life and Na-levels in body fluids are constantly monitored in the brain. The subfornical organ (SFO) is the center of the sensing responsible for the control of Na-intake behavior, where Nax channels are expressed in specific glial cells as the sodium-level sensor. Here, we show direct interaction between Nax channels and subunits of Na+/K+-ATPase, which brings about Na-dependent activation of the metabolic state of the glial cells. The metabolic enhancement leading to extensive lactate production was observed in the SFO of wild-type mice, but not of the Nax-knockout mice. Furthermore, lactate, as well as Na, stimulated the activity of GABAergic neurons in the SFO. These results suggest that the information on a physiological increase of the Na level in body fluids sensed by Nax in glial cells is transmitted to neurons by lactate as a mediator to regulate neural activities of the SFO.