Anna Wirz-Justice

..This study's failure to find significant delays to a single administration does not negate other positive findings with multiple doses, which may be necessary for a 'weak zeitgeber'...

..Affective disorder during pregnancy is a common condition requiring careful judgment to treat the depression while minimizing risk to the fetus. Following up on promising pilot trials, we studied the efficacy of light therapy...

..This is the first documentation of circadian rest-activity cycle disturbances in schizophrenia related to class of drug...

..Melatonin suppression is not necessary for a phase shift by light, and melatonin is not a 'weak' Zeitgeber relative to bright light when ambient lighting is strictly controlled...

..This pilot study investigated the rest-activity cycle of KP to see whether there were sleep-wake cycle disturbances similar to those that the authors had observed in patients with AD...

..The implications for treatment are to stabilize mood state by enhancing synchronization of the sleep-wake cycle with the biological clock (eg, with light therapy)...

..Chronobiology has provided efficacious non-pharmaceutical treatments for mood disorders (such as sleep deprivation or light therapy) as well as novel approaches to new drugs (e.g. agomelatine)...

..Thus, our data indicate that age-related changes in sleep propensity are clearly related to a reduced circadian signal opposing the homeostatic drive for sleep...

..Our data indicate that sequence learning is modulated by circadian phase, and the neurophysiological medium required for this type of learning is related to sleep...

..This finding may have important repercussions on the treatment of the illness as such that a selective suppression of EEG slow-wave activity could promote acute mood improvement...

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..The results demonstrate age- and/or gender-related modifications of well-being related to sleep deprivation and circadian phase and thus point to specific biological components of mood vulnerability...

..There was a distinct increase in staining intensity in all AD cases indicating an up-regulation of the receptor, possibly as a compensatory response to impaired melatonin levels in order to augment melatonin's neuroprotective effects...

..Our data suggest that manipulations of the circadian timing system, rather than the sleep homeostat, may offer a potential strategy to alleviate age-related decrements in sleep and daytime alertness levels...

..Not only sleepiness and circadian phase, but also age and gender are major factors that may contribute to attentional failures in extended work shifts and during nighttime work shifts...

..CONCLUSION: This multiple-nap protocol under constant-routine conditions revealed an age-dependent weaker coupling of the circadian rhythms of spindle frequency and sleep propensity to the circadian rhythm of melatonin secretion...

..In summary, the thermoregulatory system seems to be independent of the sleep homeostat, but the circadian modulation of sleepiness and sleep inertia is clearly associated with thermoregulatory changes...

..Irregular sleep-wake cycles and cognitive impairment are frequently observed in schizophrenia, however, how they interact remains unclear...

..The proposed noninvasive measurement method could find applications in sleep medicine or in other domains where knowing the exact endogenous circadian phase is important (e.g., for the timing of light therapy)...

..Major depressive disorder (MDD) is often associated with disturbances in circadian and/or sleep-wake dependent processes, which both regulate daytime energy and sleepiness levels...

..Furthermore, we demonstrate here that the nature of the learning material is a determinant factor for sleep-related alterations after declarative learning...

..In AD cases photoreceptor cells were degenerated and showed low MT1 expression...

..Besides the role of melatonin as "nature's soporific", it can also serve as nature's nocturnal vascular modulator...

..Our results can be interpreted in terms of an induction of a circadian phase delay and/or repercussions of a stronger alerting effect after blue light, persisting into the sleep episode...

..Sleep per se has no further thermoregulatory effect. Taken together, a thermophysiologic approach may provide a successful strategy to treat sleep-onset insomnia and alleviate sleep inertia...

..Here, we investigated age-related changes in homeostatic sleep regulation under low sleep pressure conditions, with respect to regional EEG differences and their dynamics...

..These results indicate that sleep loss-related decrements in planning performance depend on difficulty level, and that apparently insensitive tasks can turn out to be sensitive to sleep loss and circadian variation...

..Food may be a zeitgeber in humans for the food-entrainable peripheral oscillators, but melatonin data do not support such a conclusion for the light-entrainable oscillator in the suprachiasmatic nucleus...

..2 h; P = 0.01). Similar phase shifts were observed in CBT, DPG, and KSS ratings. In conclusion, WVD exhibit a phase delay of the endogenous circadian system with respect to their habitual sleep-wake cycle, which could be a cause of DIS...

..In order to directly test our hypothesis, further studies with thermophysiological interventions (e.g. cooling the extremities) are needed...

..On the other hand, decrements in PVT performance which were related to circadian phase did not depend significantly on any categorization (such as percentiles of the RTs)...

..The demonstration of a functional circadian machinery in human buccal samples and its response to light opens the door for investigation of human circadian rhythms at the gene level and their associated disorders...

..The challenge will be to design a computer screen with a spectral profile that can be individually programmed to add timed, essential light information to the circadian system in humans...

..Since a moderate wine intake correlates with a lower risk for Alzheimer disease (AD), an additional neuroprotective effect has been postulated for resveratrol...

..These findings provide quantitative evidence for the hypothesis that frontal brain regions are particularly vulnerable to the effects of elevated sleep pressure ('prefrontal tiredness') and ageing ('frontal ageing')...

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..Thus, even though the molecular machinery of peripheral circadian clocks does not change with age, some age-related circadian dysfunction observed in vivo might be of hormonal origin and therefore might be pharmacologically remediable...

..Our data provide evidence that the circadian pacemaker actively promotes low-frequency sleep spindles during the biological night with a parietal predominance...

..Increasing zeitgeber strength is an important strategy for improving sleep quality and timing in dementia, and DDS light therapy may provide one of the appropriate means to do so...

..In the human retina, however, immunohistochemical localization of orexins and their receptors, OX-R1 and OX-R2, has not been ascertained...

..Here, we consider light exposure and sleep deprivation (more positively known as "wake therapy") as first-line treatments for major depression, and we provide guidelines for use...

..The role of melatonin in human ocular circulation remains to be established...

..We conclude that melatonin reduces arousal and startle responsiveness. However, no evidence for a direct emotion-modulating effect of melatonin was found in this healthy cohort...

..02) and by 0.27 +/- 0.14 h for melatonin rhythms (p = 0.09). However, this advance was small to medium according to effect size. Sleep per se may feed back onto the circadian pacemaker, but it appears to be a weak zeitgeber in humans...

..The implications are far ranging concerning learning, memory, vigilance, performance, and quality of life...

..3) Given the urgent need for new strategies to treat patients with residual depressive symptoms, clinical trials of wake therapy and/or adjuvant light therapy, coupled with follow-up studies of long-term recurrence, are a high priority...