Our understanding of the ways that neuroactive steroids act in the brain has been increased by transgenic approaches, recombinant expression systems, higher resolution electrophysiological paradigms, and the development of technology to localize receptors. Recent behavioral studies examining the effects of steroids on mood, seizure susceptibility, reproductive function, and sensorimotor control have shed new light on this complex field and inspired exciting developments. Neurosteroid Effects in the Central Nervous System: The Role of the GABAA Receptor presents a complete overview of the effects of neuroactive steroids in the brain, describes new methods for investigating these effects, and features the latest theories on steroid action in the central nervous system, with emphasis on the GABAA receptor. The text discusses techniques for receptor localization and quantification, recombinant expression systems to identify steroid-responsive receptor isoforms, the use of transgenic/antisense strategies to determine steroid effects on neuronal circuits and behavior, and techniques to examine the cellular effects of steroid action in the brain. The material covers the range of steroid action on such end points as mood, cognition, epilepsy, neuroprotection, and learning/plasticity, and it describes methods using molecular, electrophysiological, and behavioral techniques to link cellular mechanisms of steroid action with behavioral effects. This timely compilation provides important insight into the possibilities for steroid effects on the central nervous system. It will appeal to the clinical, behavioral, and molecular interests of research scientists, clinicians, and students interested in broadening their knowledge about neurosteroid effects with relevance to premenstrual syndrome and post-partum changes.