Neuroactive steroids

This entry delineates the pharmacological, physiological, pathological, and therapeutic relevance of neuroactive steroids. These steroids are endogenous or synthetic compounds that can cross the blood-brain barrier and rapidly alter neuronal excitability via membrane receptors. We focus on neuroactive steroids that have specific binding sites on g-aminobutyric acid type A (GABAA) receptors which directly influence both synaptic and extrasynaptic transmission and indirectly alter many physiological processes including the hypothalamic-pituitary-adrenal (HPA) axis function, inflammation, and neuroregeneration. Neuroactive steroid levels are modulated by stress, ovarian cycle, pregnancy, as well as numerous pharmacological agents. We summarize the sites of neuroactive steroid actions, the systemic and molecular consequences of these actions, and the potential therapeutic relevance of their effects for neuropsychiatric diseases.