Sleep – Prerequisite for Health

Abstract

Sleep - one of the most important conditions of the organisms – has always attracted attention of scientists of various fields. Considering that humans spend 1/3 of life in sleep which is characterized by specific activity – dreams. Sleep, per se, was a permanent subject of interest starting from antient philosophers to the psychologists and neurophysiologists of modern times This interest had mounted especially after development of research technology, when it was established that sleep electro-encephalographically (regarding of registered electrical activity) is not homogenous simple phenomenon and is divided into slow wave sleep - NREM and fast-waved sleep REM- sleep (dreaming sleep) phases. The importance of normal sleep and its hygiene for maintaining good health is difficult to overestimate. In developed countries 1/3 of adults complain of sleep insufficiency/ disorders. Disturbances in sleep architecture are significantly reflected in the wake actions – mental processes, mood, in different neurological and psychiatric disorders/illnesses. Specific brain structures, neurotransmitters and hormones, are considered as sleep regulatory mechanisms. Sleep is a cyclic process which contains NREM and REM phases alterations and at the same time it is one of the components of a wider cycle - the sleep-wakefulness cycle (SWC). SWC with its phases and stages is one of the most important forms of brain integrative activities, and the integrity of the cycle depends on the causal relationship of the phases. SWC is a refined phenomenon with complex generation and regulation of the above-mentioned phases and the cycle as a whole depends on the normal activity of the wide spread systems of the brain and the functionality of the neurotransmission and hormonal activity; SWC is a reflection of homeostatic processes and dysregulation of these processes adversely affect the normal cycle. The aim of the presented report is a discussion of current somnological evidences, focusing on importance of some hormones in regulation of sleep (sleep on-set, promotion, maintains).