A5066128766- Circadian rhythm and melatonin
- Sleep and Wakefulness Research
- Photoreceptor and optogenetics research
- Neurobiology and Insect Physiology Research
- Spaceflight effects on biology
- Dietary Effects on Health
- Sleep and related disorders
- Neural dynamics and brain function
- Electromagnetic Fields and Biological Effects
- Adipose Tissue and Metabolism
- Light effects on plants
- Neuroscience of respiration and sleep
- Olfactory and Sensory Function Studies
- Neuroendocrine regulation and behavior
- Functional Brain Connectivity Studies
- Neuroscience and Neuropharmacology Research
- Animal Behavior and Reproduction
- Impact of Light on Environment and Health
- Cancer-related cognitive impairment studies
- COVID-19 and healthcare impacts
- Migraine and Headache Studies
- Ion channel regulation and function
- Heart Rate Variability and Autonomic Control
- Paranormal Experiences and Beliefs
- Drug Transport and Resistance Mechanisms
Leiden University
2003-2025
Leiden University Medical Center
2015-2024
Laboratory of Molecular Genetics
2008-2012
University of Calgary
2012
RELX Group (United Kingdom)
2004
University of Amsterdam
2003
Eötvös Loránd University
2003
Rijksmuseum
1996-1997
Dalhousie University
1985-1992
University of Groningen
1986-1990
Circadian rhythm disturbances are observed in, e.g., aging and neurodegenerative diseases associated with an increased incidence of obesity diabetes. We subjected male C57Bl/6J mice to constant light [12-h light-light (LL) cycle] examine the effects a disturbed circadian on energy metabolism insulin sensitivity. In vivo electrophysiological recordings in central pacemaker suprachiasmatic nuclei (SCN) revealed immediate reduction amplitude, stabilizing at 44% normal amplitude values after 4 d...
The importance of exercise for health and neurogenesis is becoming increasingly clear. Wheel running often used in the laboratory triggering enhanced activity levels, despite common objection that this behaviour an artefact captivity merely signifies neurosis or stereotypy. If wheel indeed caused by captive housing, wild mice are not expected to use a nature. This however, our knowledge, has never been tested. Here, we show when wheels placed nature, they frequently mice, also no extrinsic...
Circadian rhythms in neuronal ensemble, subpopulations, and single unit activity were recorded the suprachiasmatic nuclei (SCN) of rat hypothalamic slices. Decomposition ensemble pattern revealed that subpopulations units within SCN show surprisingly short periods enhanced electrical ≈5 h maximal at different phases circadian cycle. The summed accounts for SCN, indicating waveform is a composed tissue property. was used to simulate responsiveness neurons photoperiods. We inferred predictions...
Aging is associated with a deterioration of daily (circadian) rhythms in physiology and behavior. Deficits the function central circadian pacemaker suprachiasmatic nucleus (SCN) have been implicated, but responsible mechanisms not clearly delineated. In this report, we characterize progression rhythm mice to 900 d age. Longitudinal behavioral sleep–wake recordings up 30-month-old showed strong fragmentation rhythms, starting at age 700 d. Patch-clamp group revealed deficits membrane...
The suprachiasmatic nuclei (SCN) of the hypothalamus contain a pacemaker that generates circadian rhythms in many functions. Light is most important stimulus synchronizes to environmental cycle. In this paper we have characterized baseline neuronal firing patterns SCN as well their response light freely moving rats. Multiunit and single-unit recordings showed neurons increase discharge during daytime decrease at night. Discharge levels individual were followed throughout cycle appeared phase...
Disturbances in the circadian system are associated with development of type 2 diabetes mellitus. Here, we studied direct contribution suprachiasmatic nucleus (SCN), central pacemaker system, insulin resistance. Exclusive bilateral SCN lesions male C57Bl/6J mice, as verified by immunochemistry, showed a small but significant increase body weight (+17%), which was accounted for an fat mass. In contrast, mice collateral damage to ventromedial hypothalamus and paraventricular severe obesity...
Significance Increased light exposure has been associated with obesity in both humans and mice. In this article, we elucidate a mechanistic basis of association by performing studies We report that prolonging daily increases adiposity decreasing energy expenditure rather than increasing food intake or locomotor activity. This was caused light-exposure period-dependent attenuation the noradrenergic activation brown adipose tissue recently shown to contribute substantially converting fatty...
Significance The inhibitory neurotransmitter GABA plays an important role in many brain circuits involved anxiety, depression, epilepsy, and sleep disorders. is critical for maintaining the balance between excitatory transmission, thereby ensuring proper neuronal network function. Here, we report that entraining mice to a long-day photoperiod can modify excitatory/inhibitory suprachiasmatic by increasing GABAergic excitation. These data suggest day length affects of circadian clock. This...
The Holo-Hilbert spectral analysis (HHSA) method is introduced to cure the deficiencies of traditional and give a full informational representation nonlinear non-stationary data. It uses nested empirical mode decomposition Hilbert–Huang transform (HHT) approach identify intrinsic amplitude frequency modulations often present in systems. Comparisons are first made with spectrum analysis, which usually achieved its results through convolutional integral transforms based on additive expansions...
Abstract Exposure to light at night (LAN) is associated with insomnia in humans. Light provides the main input master clock hypothalamic suprachiasmatic nucleus (SCN) that coordinates sleep-wake cycle. We aimed develop a rodent model for effects of LAN on sleep. Therefore, we exposed male Wistar rats either 12 h (150–200lux):12 dark (LD) schedule or (150–200 lux):12 dim white (5 lux) (LDim) schedule. LDim acutely decreased amplitude daily rhythms REM and NREM sleep, further decrease over...
In mammals, sleep is controlled by a homeostatic process, which regulates depth of sleep, and the circadian clock suprachiasmatic nucleus (SCN), 24-h rhythms in timing sleep. Sleep deprivation known to cause molecular physiological changes results an alteration It generally assumed that following deprivation, mechanisms overrule clock, allowing animals during their active phase. However, recent evidence indicates states have direct access pacemaker SCN. We questioned therefore whether may...