Two oscillatory components detected by forced splitting of the sleep-wake cycle in humans (original) (raw)

American Journal of Physiology-Regulatory, Integrative and Comparative Physiology

Abstract

The sleep-wake cycle of human subjects was artificially split into two episodes by imposing an 8-h light and 4-h dark cycle (LD 8:4) twice a day for 7 days, which was followed by a 3 day free-running session. Sleep was permitted only in the dark period. The subjects in the ordinary group were exposed to ordinary light (ca. 500 lux) in the 8-h light period, and those in the bright light group to bright (ca. 5,000 lux) and ordinary light alternatively with bright light after the 1st dark period (24:00 - 4:00 h). Split sleeps persisted in the free-running session with the major episode around the 1st dark period and the minor episode around the 2nd dark. By contrast, circadian melatonin rhythm in the free-running session significantly phase-delayed in the ordinary light group, but phase-advanced in the bright light group, keeping the melatonin rhythm un-split. The length of nocturnal melatonin secretion (NMS) was significantly shortened in the bright light group. Interestingly, the fal...

Yujiro Yamanaka hasn't uploaded this paper.

Let Yujiro know you want this paper to be uploaded.

Ask for this paper to be uploaded.