Mineralocorticoid receptor expression and increased survival following neuronal injury.

Glucocorticoids, acting via the mineralocorticoid receptor, are required for granule neuronal survival in the rat dentate gyrus. Whether this mineralocorticoid receptor-mediated neuroprotective effect has more general applicability is unknown. Here we report increased mineralocorticoid receptor expression in rat hippocampal and cortical neurons exposed in vitro to low levels of staurosporine and in rat hippocampal pyramidal neurons exposed in vivo to hypothermic transient global ischaemia. In both the cell culture system and the in vivo system increased mineralocorticoid receptor expression is associated with increased neuronal survival, and this increase is reversed by mineralocorticoid receptor antagonism. Modulation of mineralocorticoid receptor gene expression may therefore be an important target for reduction of brain injury in conditions caused by cerebral ischaemia including brain damage following cardiac arrest and stroke.