title: Circadian peculiarities of daytime sleep in 1 to 6 months old infants (electrophysiological study).
abstract: A longitudinal study of 6 normal, full-term infants was carried out. Polygrams of three subsequent daytime sleep periods (morning, noon, afternoon) were recorded at monthly intervals. It was established that: (a) Over the first 3 postnatal months the noon period was the longest (98.96 min), and each sleep period consisted most frequently of 2 cycles. Over the second 3 months the afternoon period shortened significantly from 68.69 min to 41.92 min and consisted exclusively of 1 cycle. (b) The delta sleep percentage was the greatest (52%) over the first 3 months in the morning period and over the second 3 months it was almost equal in all the three periods. The paradoxical sleep percentage over the first 3 postnatal months was equal in all the three periods, but over the second 3 months it became smaller in the afternoon period, (c) The heart rate values were lowest in the morning period, this phenomenon being clearly expressed during the delta sleep. One minute time (in sec), occupied by REMs, was evaluated and it was found that this parameter was not influenced by age and timing of sleep periods, but there existed positive correlation between this time and the duration of the paradoxical phase under estimation.
mesh_terms: D002940:Circadian Rhythm; D003700:Delta Rhythm; D004562:Electrocardiography; D004569:Electroencephalography; D004584:Electronystagmography; D005260:Female; D006339:Heart Rate; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008137:Longitudinal Studies; D008297:Male; D012890:Sleep / Q000502:physiology*; D012895:Sleep, REM / Q000502:physiology