Corticosteroids in the brain - Cellular and molecular actions

The rat adrenal hormone corticosterone reaches the brain and binds to intra cellular receptors. These receptors comprise high-affinity mineralocorticoi d and lower-affinity glucocorticoid receptors that, upon activation, affect the transcription rate of specific genes. The two receptor types are discr etely localized in the brain, with particularly high expression levels in t he hippocampus. Here we review recent studies showing that electrical prope rties and structural aspects of hippocampal principal neurons are specifica lly regulated by mineralocorticoid- or glucocorticoid-receptor activation. The molecular mechanisms by which these cellular effects could be accomplis hed are discussed.