Abstract
This study investigated the effects of the length of sleep interruption on body temperature. Subjects were 5 male students mean aged 21.1 years old (19.5-22.1). We recorded polysomnography with measurement of rectal temperature (RT) during a whole night. Following two adaptation and one baseline nights, four consecutive nights were interrupted once a night at 20 min after the onset of NREM sleep in the 2nd sleep cycle. The length of sleep interruption was set at 10, 40, 60 and 90 min. When sleep interruptions were of 10-min and 40-min length, temporal patterns of RT were not different from the baseline night which was not interrupted. When the length of sleep interruption was 60 or 90 min, drops of RT during the interval from the second lights-out to the point an hour after the second sleep onset were significantly larger in both conditions than in10-min condition. In addition, the temporal position of minimum RT tended to be earlier as the interruption length was extended. The minimum RT appeared earliest when sleep interruption was 90 min. There was no significant correlation between the drop of RT and the amount of SWS (slow wave sleep) during the period of 60 min after the 1st and 2nd sleep onset, suggesting that the drop of RT appears irrespective of the amount of SWS.
