ABSTRACT
The term neurosteroid, as originally conceived in 1981 by Baulieu, referred to steroids that are synthesized locally within the brain either from cholesterol or steroid hormone precursors (1). More recently, the term has been used in reference to steroids that rapidly alter the excitability of neurons by binding to membrane-bound receptors such as those for inhibitory or excitatory neurotransmitters (2). In common usage, neurosteroid is generally understood to mean an endogenous steroid (whether peripherally synthesized or brain derived) that acts on the nervous system in a non-classical fashion, that is, via cellular actions that do not involve steroid nuclear hormone receptors. The term neuroactive steroid encompasses naturally occurring neurosteroids and their synthetic analogs with similar biological properties.
