A short‐term poikilothermic period occurs just after paradoxical sleep onset in humans: characterization changes in sweating effector activity

Abstract

SUMMARYWe examined the changes in sudorific effector activity in five healthy young (21 -23 y) subjects just before, during and just after successive paradoxical sleep (PS) phases. Local sweat rates were evaluated minute by minute over the chest (mcs). Previous observations, showing that mLs levels dropped before paradoxical sleep onset was electrophysiologically scored, were confirmed. At the end of this period of m,, depression, which in the present study coincided with paradoxical sleep onset, we show for the first time a short period (3-7min) (period I) during which sweat production completely disappeared. A second period then followed (period II), at the very beginning of which mcs was re-elicited and thereafter increased in close correlation with paradoxical sleep duration. During period 11, the remaining inhibiting influences (maximal during period I) and their releases could be specified by the successive valleys (indicating mch inhibition) and peaks (indicating release of the mc5 inhibition) drawn by the minute by minute mc, changes. These inhibitions became weaker as paradoxical sleep advanced. Given the strategic position of period I (at paradoxical sleep onset) and the total m,, abolition therein observed, it may be assumed that this poikilothermic state is the re-emergence of the 'ancestral' mode of body temperature regulation. From a thermophysiological point of view, period I1 may be considered as more 'modern' and directly related to the extension of paradoxical sleep in humans. This extension could be underlain by the unique development of our cognitive and/ or learning functions.

Physiological correlates of eye movement desensitization and reprocessing

“…One of the most consistent pattern of REM-sleep is a depressed thermoregulatory response, with a decreased difference between core and peripheral temperature (Glotzbach & Heller, 2000). The immediate increase of skin temperature during eye movements and the decrease immediately after eye movements support the REM-related hypothesis because the thermoregulatory control of core-toperipheral temperature is suspended in REM-sleep, and episodes of phasic REM-sleep is closely linked to rapid temperature increases in the extremities, at least during non-extreme ambient temperatures (Dewasmes, Bothorel, Candas, & Libert, 1997;Henane, Buguet, Roussel, & Bittel, 1977). Furthermore, the eye movements during REM-sleep are associated with hypoventilation and rapid shallow breathing (Douglas, White, Pickett, Weil, & Zwillich, 1982;Gould et al, 1988;Millman et al, 1988), and due to a decrease in minute ventilation the levels of end-tidal PCO 2 is increased (Schäfer & Schläfke, 1998).…”

Effects of thermal environment on sleep and circadian rhythm

“…In addition, the sweat rate increases during SWS compared to other sleep stages [29], while delayed onset of sweating [30] and a decreased sweat rate [31] decrease evaporative heat dissipation and reduce heat tolerance during REM. Interestingly, the decreased sweat rate during REM is observed prior to REM stage onset [32]. Considering that skin sympathetic nerve activity (SSNA) contains sudomotor activity synchronous with vasodilator activity [33], this result indicates that SSNA might precede the sleep stage shift corresponding with heart rate variability (HRV) preceding the sleep stage shift at the sleep onset period [14].…”

Geoclimatology and sleep in Africa: A mini-review

“…Therefore, it is not surprising that individuals living under climatic heat load will enhance stage N3. Contrarily, stage R is a state of poor thermoregulation, i.e., almost a poikilothermic state [49]. Sweating slows down, thus decreasing body thermal loss [1], and skin and central temperatures increase in the heat.…”