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The roles of metabolic heat production, arterial blood flow and temperature in the genesis of the brain temperature increase related to REM sleep occurrence in several mammalian species are discussed on the basis of available experimental evidence. The experimental data show that only changes in arterial blood flow and temperature consistently underlie the(More)
This study was carried out in order to further test the hypothesis that the occurrence of REM sleep in the rat in the form of episodes separated by long intervals (single REM sleep episodes) and by short intervals (sequential REM sleep episodes) is differently influenced by changes in both sleep and ambient related processes. Rats were studied during the(More)
The behavioral state-dependent changes in the hypothalamic temperature of homeotherms reflect extracerebral adjustments in circulatory variables to influence the temperature and flow of the arterial blood cooling the brain. There are different mechanisms for brain cooling, i.e. systemic and selective brain cooling, which are affected by the changes in body(More)
Both circulation and breathing show basic differences in regulation between synchronized sleep and desynchronized sleep. Closed-loop operations of automatic control mechanisms during synchronized sleep ensure an efficient and steady regulation of such functions as in wakefulness, although at a lower level of energy expenditure. In contrast, a change in the(More)
STUDY OBJECTIVES Exposure to low ambient temperature (Ta) depresses REM sleep (REMS) occurrence. In this study, both short and long-term homeostatic aspects of REMS regulation were analyzed during cold exposure and during subsequent recovery at Ta 24 degrees C. DESIGN EEG activity, hypothalamic temperature, and motor activity were studied during a 24-h(More)
Studies on the interaction between sleep and thermoregulation are reviewed with regard to the processes underlying the ultradian evolution of behavioral states. The experimental evidence shows that thermoregulatory mechanisms influence the waking-sleeping cycle in both the absence or the presence of a thermal load. Such a control appears to be a functional(More)
The effects of the rhythmical delivery of an auditory stimulus (1000 Hz, from 50 to 100 dB, 20 ms, every 20 s) on the pattern of rapid eye movement (REM) sleep occurrence was studied in the rat. The stimulation was simultaneously carried out on pairs of rats over 5 consecutive days (10-h recording sessions), during which a tone of increasing intensity (50,(More)
The influence of changes in heat loss at specific heat exchangers, appraised by recording ear skin temperature (Ts), on the hypothalamic temperature (Thy) rise during desynchronized sleep (DS) was studied in unrestrained cats at different ambient temperatures (Ta). The correlations of initial and final Thy changes (delta iThy and delta fThy) with initial(More)
The present research studied the mechanisms underlying the increase in brain temperature during REM sleep in the unrestrained rabbit carrying chronically implanted electrodes, thermistors and common carotid artery occluders. During the ultradian wake-sleep cycle at constant ambient temperature (25+/-2 degrees C), we recorded: (i) the ear pinna temperature(More)