[Ontogenesis of sleep-wakefulness regulation]

In addition to traditional opinions endogenous sleep factors play an important role in modern concepts concerning sleep-wake regulation. The recent development of neurochemical research including experiments with neuropeptides has modified the classical theories of sleeping and waking. Moreover, the influence of hormones as cortisol or prolactin on neurotransmitters involved in sleep-wake regulation, special problems of the endogenous sleep-rhythms, and the conditions of the ontogenetic development are discussed. In addition, a new concept, the so-called Stimulation theory is described.