The role of the central monoaminergic system and rapid eye movement sleep in development.

Transmission of information in the brain is of a chemical nature. Neurotransmitters are present at very early stages of brain development, having trophic effects on maturation of target neurons as well as mediating the behavioral repertoire of the immature brain. Many centrally acting psychoactive drugs which are commonly used (also during pregnancy) for treatment of depression, asthma, hypertension, epilepsy, parkinsonism, hyperkinetism and other neurological and psychiatric disorders act directly on brain neurotransmitters (in particular monoamines) and behavioral states. Disturbances observed later in life in animals and man, as a result of early interference with brain neurotransmitters, using these drugs, are not gross physical malformations but are in fact subtle behavioral and neurological symptoms such as hyperactivity, emotional lability, attentional distractability and sleep disturbances, similar to symptoms observed in the minimal brain dysfunction syndrome.