Book excerpt: Investigators critically evaluate the latest information on how anesthetics work at the molecular, cellular, organ, and whole animal level. They review anesthetic effects on memory, consciousness, and movement and spell out in detail both the anatomic structures and physiological processes that are their likely targets, as well as the cellular and molecular mechanisms by which they operate. This text draws together and reviews all the recent research on anesthetic mechanisms, highlighting the precise routes along which these substances operate, and how this deeper understanding will lead to the design of effective drugs free of undesirable side effects.