Excessive aldosterone production increases the risk of heart disease, stroke, dementia, and death. Aldosterone increases both sodium retention and sodium consumption, and increased sodium consumption may worsen end-organ damage in patients with aldosteronism. Preventing this increase could improve outcomes, but the behavioral mechanisms of aldosterone-induced sodium appetite remain unclear. In rodents, we previously identified aldosterone-sensitive neurons, which express the mineralocorticoid receptor and its prereceptor regulator, 11-β-hydroxysteroid dehydrogenase 2 (HSD2). In the present study, we identified HSD2 neurons in the human brain and then used a mouse model to evaluate their role in aldosterone-induced salt intake. First, we confirmed that dietary sodium deprivation increases aldosterone production, salt intake, and HSD2 neuron activity. Next, we showed that continuous chemogenetic stimulation of HSD2 neurons causes a large and specific increase in salt intake. Finally, we used dose-response studies and genetically targeted ablation of HSD2 neurons to show that these neurons are necessary for aldosterone-induced salt intake. Identifying HSD2 neurons in the human brain and establishing their necessity for aldosterone-induced salt intake in mice improves our understanding of appetitive circuits and highlights this small cell population as a therapeutic target for moderating dietary sodium.
Keywords: Behavior; Endocrinology; Mouse models; Neuroendocrine regulation; Neuroscience.