Publications by authors named "Carolin Franziska Reichert"

3 Publications

  • Page 1 of 1

Caffeine-dependent changes of sleep-wake regulation: Evidence for adaptation after repeated intake.

Prog Neuropsychopharmacol Biol Psychiatry 2020 04 19;99:109851. Epub 2019 Dec 19.

Centre for Chronobiology, Psychiatric Hospital of the University of Basel, Basel, Switzerland; Transfaculty Research Platform Molecular and Cognitive Neurosciences, University of Basel, Basel, Switzerland.

Background: Circadian and sleep-homeostatic mechanisms regulate timing and quality of wakefulness. To enhance wakefulness, daily consumption of caffeine in the morning and afternoon is highly common. However, the effects of such a regular intake pattern on circadian sleep-wake regulation are unknown. Thus, we investigated if daily daytime caffeine intake and caffeine withdrawal affect circadian rhythms and wake-promotion in habitual consumers.

Methods: Twenty male young volunteers participated in a randomised, double-blind, within-subject study with three conditions: i) caffeine (150 mg 3 x daily for 10 days), ii) placebo (3 x daily for 10 days) and iii) withdrawal (150 mg caffeine 3 x daily for eight days, followed by a switch to placebo for two days). Starting on day nine of treatment, salivary melatonin and cortisol, evening nap sleep as well as sleepiness and vigilance performance throughout day and night were quantified during 43 h in an in-laboratory, light and posture-controlled protocol.

Results: Neither the time course of melatonin (i.e. onset, amplitude or area under the curve) nor the time course of cortisol was significantly affected by caffeine or withdrawal. During withdrawal, however, volunteers reported increased sleepiness, showed more attentional lapses as well as polysomnography-derived markers of elevated sleep propensity in the late evening compared to both the placebo and caffeine condition.

Conclusions: The typical pattern of caffeine intake with consumption in both the morning and afternoon hours may not necessarily result in a circadian phase shift in the evening nor lead to clear-cut benefits in alertness. The time-of-day independent effects of caffeine withdrawal on evening nap sleep, sleepiness and performance suggest an adaptation to the substance, presumably in the homeostatic aspect of sleep-wake regulation.
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April 2020

Sleep-Wake Regulation and Its Impact on Working Memory Performance: The Role of Adenosine.

Biology (Basel) 2016 Feb 5;5(1). Epub 2016 Feb 5.

Centre for Chronobiology, Psychiatric Hospital of the University of Basel, Wilhelm Klein-Strasse 27, Basel 4012, Switzerland.

The sleep-wake cycle is regulated by a fine-tuned interplay between sleep-homeostatic and circadian mechanisms. Compelling evidence suggests that adenosine plays an important role in mediating the increase of homeostatic sleep pressure during time spent awake and its decrease during sleep. Here, we summarize evidence that adenosinergic mechanisms regulate not only the dynamic of sleep pressure, but are also implicated in the interaction of homeostatic and circadian processes. We review how this interaction becomes evident at several levels, including electrophysiological data, neuroimaging studies and behavioral observations. Regarding complex human behavior, we particularly focus on sleep-wake regulatory influences on working memory performance and underlying brain activity, with a specific emphasis on the role of adenosine in this interplay. We conclude that a change in adenosinergic mechanisms, whether exogenous or endogenous, does not only impact on sleep-homeostatic processes, but also interferes with the circadian timing system.
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February 2016

Fighting Sleep at Night: Brain Correlates and Vulnerability to Sleep Loss.

Ann Neurol 2015 Aug 30;78(2):235-47. Epub 2015 Jun 30.

Center for Chronobiology, Psychiatric Hospital of the University of Basel, Basel, Switzerland.

Objective: Even though wakefulness at night leads to profound performance deterioration and is regularly experienced by shift workers, its cerebral correlates remain virtually unexplored.

Methods: We assessed brain activity in young healthy adults during a vigilant attention task under high and low sleep pressure during night-time, coinciding with strongest circadian sleep drive. We examined sleep-loss-related attentional vulnerability by considering a PERIOD3 polymorphism presumably impacting on sleep homeostasis.

Results: Our results link higher sleep-loss-related attentional vulnerability to cortical and subcortical deactivation patterns during slow reaction times (i.e., suboptimal vigilant attention). Concomitantly, thalamic regions were progressively less recruited with time-on-task and functionally less connected to task-related and arousal-promoting brain regions in those volunteers showing higher attentional instability in their behavior. The data further suggest that the latter is linked to shifts into a task-inactive default-mode network in between task-relevant stimulus occurrence.

Interpretation: We provide a multifaceted view on cerebral correlates of sleep loss at night and propose that genetic predisposition entails differential cerebral coping mechanisms, potentially compromising adequate performance during night work.
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August 2015