Sleep Patterns and the Efficiency of the Gentle Methods of Sleep Deprivation in Pregnant Rats: Behavioral Study

In Wistar rats, pregnant or not pregnant, sleep-wakefulness parameters were registered for 2 days from 10:00 till 14:00. Later, these rats were sub jected to 3-hour (11:00-14:00) dady sleep deprivation (SD) during 3 consecutive days. To prevent sleep, the following manipulations were used: acoustic stimulation from moving of the food pellets, opening or horizontal rotation of the cage and gentle handling. Control pregnant or Hot pregnant rats were placed in individual cages in the same room, but their sleep was not disturbed. On average, not pregnant rats spent about 65% of the time in sleep. Sleep episodes were mostly short (less than 1 min) or medium (1-15 min). After the beginning and with advance of pregnancy, the amount. deepness and duration of sleep episodes increased. With the methods of SD used, not pregnant rats did [lot sleep almost at all during the SE) session. In pregnant rats, the quantity and intensity of stimuli used for SD increased as compared to control, which was indicatives of the growth of "sleep pressure" during pregnancy.