Journal of sleep research
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Journal of sleep research · Mar 2011
Orexin-B-saporin lesions in the lateral hypothalamus enhance photic masking of rapid eye movement sleep in the albino rat.
The 24-h distribution of rapid eye movement (REM) sleep is known to be deeply reshaped among albino rats with neurotoxic lesions in the lateral hypothalamus (LH) or among rodent models of human narcolepsy-cataplexy, with selective damage of orexinergic neurones. We explored the hypothesis that this phenomenon is explained by an enhancement of REM sleep photic masking, as a consequence of damage in the LH. Orexin-B-saporin neurotoxic lesions were induced in the LH of male Sprague-Dawley rats. ⋯ After transference to a skeleton photoperiod, lesioned rats exhibited an 88% increase in REM sleep during the rest phase, recovering the characteristic rest phase preference of REM sleep observed among control rats. The increase in rest phase REM sleep during the skeleton photoperiod was correlated positively with the magnitude of the LH lesion. Our results suggest that changes in the temporal organization of sleep-wake states observed among rats with neurotoxic lesions in the lateral hypothalamus and rodent models of narcolepsy-cataplexy may be explained by the enhancement of photic masking.
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Journal of sleep research · Dec 2010
Randomized Controlled TrialA two-part, double-blind, placebo-controlled trial of exogenous melatonin in REM sleep behaviour disorder.
Rapid eye movement (REM) sleep behaviour disorder (RBD) has been suggested to predict the development of neurodegenerative disorders. Patients with RBD are acting out dream behaviour associated with loss of normal muscle atonia of REM sleep. The aim of the present study was to confirm that exogenous melatonin improves RBD. ⋯ Interestingly, the number of REM sleep epochs without muscle atonia remained lower in patients who took placebo during Part II after having received melatonin in Part I (-16% compared to baseline; P = 0.043). In contrast, patients who took placebo during Part I showed improvements in REM sleep muscle atonia only during Part II (i.e. during melatonin treatment). The data suggest that melatonin might be a second useful agent besides clonazepam in the treatment of RBD.
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Journal of sleep research · Jun 2010
Short sleep duration and long spells of driving are associated with the occurrence of Japanese drivers' rear-end collisions and single-car accidents.
Sleepiness and fatigue are important risk factors for traffic accidents. However, the relation between the accident type and lack of sleep as well as spells of driving has not been examined sufficiently. This study aimed to clarify that short sleep duration and long spells of driving are more associated with rear-end collisions and single-car accidents as compared with accidents of other types in cases of people who cause accidents. ⋯ Logistic regression analysis showed that short nocturnal sleep (<6 h) and 10-min increments of spells of driving were significantly associated not only with rear-end collisions but also with single-car accidents as compared with accidents of other types. Furthermore, younger age (
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Journal of sleep research · Jun 2010
The effects of sleep deprivation in humans: topographical electroencephalogram changes in non-rapid eye movement (NREM) sleep versus REM sleep.
Studies on homeostatic aspects of sleep regulation have been focussed upon non-rapid eye movement (NREM) sleep, and direct comparisons with regional changes in rapid eye movement (REM) sleep are sparse. To this end, evaluation of electroencephalogram (EEG) changes in recovery sleep after extended waking is the classical approach for increasing homeostatic need. Here, we studied a large sample of 40 healthy subjects, considering a full-scalp EEG topography during baseline (BSL) and recovery sleep following 40 h of wakefulness (REC). ⋯ On the contrary, sleep deprivation has opposite effects on alpha and sigma activity in both states. In particular, this analysis points to the presence of state-specific homeostatic mechanisms for NREM sleep, limited to <2 Hz frequencies. In conclusion, REM sleep and NREM sleep seem to share some homeostatic mechanisms in response to sleep deprivation, as indicated mainly by the similar direction and topography of changes in low-frequency activity.