Consciousness, sleep, anesthesia. What are we thinking about? Part I. Physiology of consciousness and sleep

Consciousness control is one of the main objectives for anesthesiologists and intensive care specialists. Research of mechanisms of consciousness and influence of anesthetic drugs has been ongoing since the beginning of the last century. Over time, these researches have evolved from biophysical and molecular approaches to complementary systemic neurobiology. The first part of the manuscript is devoted to basic concepts and theories of consciousness, criteria of consciousness, sleep, anesthesia and coma. The most famous modern mechanisms of consciousness are presented: global neural space (B. Baars; 1988), integrative information (G. Tononi; 2004), recurrent processing (V. Lamme, 2002). Structure and stages of sleep with appropriate electroencephalographic signs are explained in detail. The fundamentals of physiology of consciousness and sleep are necessary for studying the mechanisms of action of anesthetics and understanding their effects in anesthesia.