Effects on Behavioral State Development

The REM state may have a special function in the maturation of the central nervous system in the developing organism (ref. 116). In addition it may play a role in information processing and/or the maintenance of nervous system function in the adult (ref. 117). Therefore, REM sleep, or some of the brain mechanisms underlying its characterizing phenomena, may play an essential role in brain plasticity during development as well as in adulthood. A normal development of the association of state characteristics may be essential for normal brain function. Deviations in this association or in other aspects of state organization may be related to neurobehavioral disturbances (refs. 114, 118, 119). 

Denenberg et al. (ref. 127) showed that the development of behavioral states in newborn rabbits was markedly changed for at least 40 days after one single theophylline injection on the first day of life. REM sleep vas suppressed, the development of quiet sleep vas delayed, and the level of wakefulness vas increased. The development of behavioral states in rabbits 

Hilakivi (ref. 128) found that in rats prenatal alcohol exposure during the entire period of pregnancy resulted in less active sleep, more wake and a more frequent interruption of the quiet sleep state by waking episodes on neonatal age. Human newborns with FAS may show abnormal EEG profiles and sleep disturbances such as reduced REM sleep (ref. 25). 

This information suggests that early pharmacological REM sleep suppression or other types of state disorganization may disrupt brain and behavioral development. Behavior in adulthood may still be changed as a consequence of the abnormal development, but also as a result of the aberrant adult sleep pattern. Therefore, chronic early REM sleep-like state suppression or other types of state disorganization may be important neurobehavioral teratogenic mechanisms (see also refs. 77, 118, 129). 

There is a vast amount of literature on the effects of chemicals on behavioral development. In many cases, other effects are also found, such as changes in physical development (body weight, eye opening, incisor eruption, testes descent or vaginal patency). Effects on behavior are often found with doses that do not seem to cause other easily observable physical effects. This has been shown, for example, for the effect of methylmercury on swimming 

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