Molecular genetics, circadian rhythms and sleep

摘要: Sleep is a vital function present in all mammals and birds, but its phylogenetic origin remains uncertain. In humans, sleep represents over half the first year of life, roughly third adult life. The total suppression will provoke death animals [179]. universal irrevocable nature this function, as well maintenance (conservation) NREM -REM organisation birds implies existence constitutional factors. However, wide variability phenotypes has been noted between species, animal strains individuals same duration REM their distribution throughout nycthoemeral cycle. These variations may be attributed to environmental Their role known whether terms physical effects (light, temperature) or behavioural (conditioning, diet). But these factors do not fully account for observed physiological differences “sleep” both suggesting that polymorphic genetic are involved function. Even relatively simple anatomically localised such circadian rhythmicity suprachiasmatic nucleus, multiple genes appear involved. situation probably even more complex normal abnormal regulation general. Several disorders (narcolepsy, certain forms insomnia, apnoea syndrome, restless legs syndrome periodic limb movement disorder) occur with high frequency families, higher rate concordance monozygotic than dizygotic twins, thus presence predisposing mutations polymorphisms result pathological whereas others contribute interindividual various aspects sleep.