The Influence of Antarctic Environment on Sleep in Man : Part 2. Autonomic Functions and States of Sleep (Biology and Medical Science)

• Main Author: Osamu ARAKI
• Format: Report
• Language: English
• Published: Department of Neurosurgery, Hiroshima University School of Medicine 1980
• Subjects: Antarctic; Syowa Station; Antarc*; Antarctica; Memoirs of National Institute of Polar Research; Polar Research
• Online Access: https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=674; http://id.nii.ac.jp/1291/00000674/; https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=674&item_no=1&attribute_id=18&file_no=1

Five healthy male subjects, members of the Japanese wintering party, participated in the investigation of seasonal changes in autonomic functions during sleep, besides relationship between autonomic functions and states of sleep at Syowa Station, Antarctica. Sleep polygraphic recordings including the indices of autonomic nervous system responses such as heart rate, respiratory rate, digital plethysmogram and skin potential reflex, were performed before the departure for Antarctica, in Antarctica and after returning to Japan. Mean heart rate during the whole night tended to increase in early-term in Antarctica, whereas mean respiratory rate during the whole night tended to decrease in the same period. On the other hand, with respect to heart rate during a shift from sleep cycle 1 to 4, it tended to increase or at least tended not to decrease in the first period of sleep in the course of all night sleep in Antarctica, whereas it tended to decrease progressively from the onset of sleep until the final sleep cycle in Japan. Furthermore, heart rate during SWS in sleep cycle 1 showed a negative correlation with %S4 of total sleep time. The results indicate that the sympathetic tone in the first period of sleep was enhanced by the low environmental temperature in Antarctica and suggest that proportion of SWS was modulated, at least in part, via the hypothalamus.