Aldosterone in the brain

Geerling JC, Loewy AD. Aldosterone in the brain. Am J Physiol Renal Physiol 297: F559-F576, 2009. First published March 4, 2009; doi:10.1152/ajprenal.90399.2008. Pharmacological and physiological phenomena suggest that cells somewhere inside the central nervous system are responsive to aldosterone. Here, we present the fundamental physiological limitations for aldosterone action in the brain, including its limited blood-brain barrier penetration and its substantial competition from glucocorticoids. Recently, a small group of neurons with unusual sensitivity to circulating aldosterone were identified in the nucleus of the solitary tract. We review the discovery and characterization of these neurons, which express the enzyme 11 beta-hydroxysteroid dehydrogenase type 2, and consider alternative proposals regarding sites and mechanisms for mineralocorticoid action within the brain.