[Respiratory muscle activity in newborn children during sleep and wakefulness].

Two types of electrical activity - inspiratory and tonic (postural) ones - have been registered in the external intercostal muscles and diaphragm. Both types of the activity decrease during orthodoxical sleep as compared with the period of quiet awakefulness. During the transition of orthodoxical sleep into paradoxical one, tonic activity is completely inhibited, while inspiratory activity in the intercostal muscles remains unchanged, being increased in the diaphragm. In the period of rapid eye movements inspiratory activity of the intercostal muscles is reduced. The decreased tone of the intercostal muscles accounts for changes in respiratory movements and for the onset of asynchoronous thoracic and abdominal respiratory movements during paradoxical sleep.