Neuroactive steroids and the nervous system: further observations on an incomplete tricky puzzle.

In the last 15 years, the study of the interactions between steroids, now named neuroactive steroids, and the nervous system has received great attention from the scientific community (e.g. the determination of various signalling pathways involving classical and nonclassical steroid receptors, their role in sexual differentiation of the brain, and in the control of reproduc- tion and behaviours). These molecules may also represent interesting tools for therapeutic strategies against neurodegenera- tive and psychiatric disorders, which, in many cases, show sex dif- ferences in their incidence, symptomatology, neurodegenerative outcome and, interestingly, in the levels of neuroactive steroids