[Actions of neuroactive steroids in neurons]

The term "neuroactive steroids" applies to those steroids that have biological activities in nervous system. These neuroactive steroids can be divided into three categories according to the mechanism of their effects: (1) Effects mediated by membrane receptors including GABAA receptor and NMDA receptor that are ion channels; (2) Effects mediated by membrane receptors that are coupled with second messenger systems; (3) Effects mediated by intracellular receptors which in turn modulate gene expression. These neuronal effects of steroids, especially modulation of the ion-channel receptor and G protein--coupled receptor, have drawn more attention of the researchers.