The induction of corticosteroid actions on membrane properties of hippocampal CA1 neurons requires protein synthesis.

Corticosterone can affect electrical properties of CA1 pyramidal neurons via binding to two corticoid receptor types, the mineralocorticoid (MR) and glucocorticoid receptor (GR). Previously we have shown that MR-activation leads to attenuation of serotonin (5-HT)-induced membrane hyperpolarization, while GR-activation induces an increase in the amplitude of the afterhyperpolarization (AHP) following a short current pulse. In this study we show that the MR- and GR-mediated changes of the membrane properties are prevented in the presence of the protein synthesis inhibitor cycloheximide, thus suggesting a genomic action of the steroids.