[Sleep, memory and learning].

Recent studies have demonstrated that while we are sleeping, our brain is very busy processing all information we have acquired along the day. Lack of sleep has shown to produce deficits in memory consolidation and plays an important role in brain development and brain plasticity in the several developmental stages of the human brain. At the cellular level, circadian cycles coordinate complex mechanism that "turn on and off" genes and cellular structures regulating individual cell functions to impact global organ and systems physiological activities. At the end a perfect and coordinated equilibrium in the mental, emotional and physiological is the goal of this complex process. Sleep impacts memory, learning, mood, behavior, immunological responses, metabolism, hormone levels, digestive process and many more physiological functions. We present a review of three basic aspects related with sleep: a. brain electrical activity during the sleep and neuroanatomic correlation with mechanism related with memory and learning; b. circadian cycles and impact in several physiological systems; c some examples of clinical disorders associated with sleep disorders and impact in learning and memory.