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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)
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)
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)
Since REM sleep is characterized by a suspension of the hypothalamic integration of homeostatic regulations, it has been assumed that the duration of both REM sleep episodes and of the time interval between the end of one episode and the beginning of the following episode may be regulated according to sleep related processes and the homeostatic needs of the(More)
STUDY OBJECTIVES Acute exposure to low ambient temperature modifies the wake-sleep cycle due to stage-dependent changes in the capacity to regulate body temperature. This study was carried out to make a systematic analysis of sleep parameters during the exposure to different low ambient temperatures and during the following recoveries at ambient temperature(More)
In the rat the exposure to an ambient temperature (Ta) of -10 degrees C induces an almost total REM sleep deprivation that results in a proportional rebound in the following recovery at normal laboratory Ta when the exposure lasts for 24 h, but in a rebound much lower than expected when the exposure lasts 48 h. The possibility that this may be related to(More)
The occurrence of REM sleep episodes, separated by intervals >3 min (single episodes) and < or =3 min (sequential episodes), was determined in the rat during the recovery (ambient temperature (Ta) 23 degrees C, L period of the LD [12 h:12 h]-cycle), which followed the exposure to low Ta (0 and -10 degrees C) during the D period of the previous LD-cycle,(More)
A shift of physiological regulations from a homeostatic to a non-homeostatic modality characterizes the passage from non-NREM sleep (NREMS) to REM sleep (REMS). In the rat, an EEG index which allows the automatic scoring of transitions from NREMS to REMS has been proposed: the NREMS to REMS transition indicator value, NIV [J.H. Benington et al., Sleep 17(More)
The accumulation of adenosine 3':5'-cyclic monophosphate (cAMP) was measured in the preopticanterior hypothalamic area, the cerebral cortex, and the hippocampus of rats exposed to different ambient temperatures: (1) 23 +/- 0.5 degrees C, for 53 h +/- 20 min (control); (2) -10 +/- 1 degrees C, for 53 h +/- 20 min (exposure to low ambient temperature); (3)(More)
From a physiological viewpoint, REM sleep (REMS) is a period during which homeostatic physiological regulations are impaired. In the rat, REMS occurs in two forms respectively characterized by episodes separated by long intervals (single REMS episodes) and by episodes which have short intervals and occur in sequences (REMS clusters). Since the partition of(More)