A5085778405- Circadian rhythm and melatonin
- Bat Biology and Ecology Studies
- Sleep and Wakefulness Research
- Sleep and related disorders
- Adipose Tissue and Metabolism
- Dietary Effects on Health
- Neurobiology and Insect Physiology Research
- Neuroendocrine regulation and behavior
- Photoreceptor and optogenetics research
- Light effects on plants
- Neuroscience and Neuropharmacology Research
- Physiological and biochemical adaptations
- Receptor Mechanisms and Signaling
- Neural dynamics and brain function
- Genetics, Aging, and Longevity in Model Organisms
- Pharmacological Effects and Assays
- Animal Behavior and Reproduction
- Cognitive Abilities and Testing
- Children's Physical and Motor Development
- Environmental DNA in Biodiversity Studies
- Early Childhood Education and Development
- Memory and Neural Mechanisms
- Thermal Regulation in Medicine
- Birth, Development, and Health
- Impact of Light on Environment and Health
University of Oxford
2019-2024
University of Massachusetts Chan Medical School
2017-2022
Williams College
2020-2022
University of Groningen
2010-2019
Significance The circadian system drives daily rhythms in physiology and behavior. Mammals nature can change their activity rhythms, but causes consequences of this behavioral plasticity are unknown. Here we show that nocturnal mice become diurnal when challenged by cold or hunger. Negative energy balance changes hormonal, physiological without modifying the rhythm pacemaker suprachiasmatic nucleus. This response is adaptive because during daytime warmth resting a buffered environment...
Circadian clocks of adolescents typically run late—including sleep times—yet generally are expected at school early in the morning. Due to this mismatch between internal (circadian) and external (social) times, suffer from chronic deficiency, which, turn, affects academic performance negatively. This constellation students’ future career prospects. Our study correlates chronotype examination performance. In total, 4734 grades were collected 741 Dutch high students (ages 11-18 years) who had...
Abstract Maximising survival requires animals to balance the competing demands of maintaining energy and avoiding predation. Here, quantitative modelling shows that optimising daily timing activity rest based on encountered environmental conditions enables small mammals maximise survival. Our model nocturnality is typically beneficial when predation risk higher during day than night, but this reversed by energetic benefit diurnality food becomes scarce. Empirical testing under semi‐natural...
Abstract Success at school determines future career opportunities. We described a time-of-day specific disparity in performance between early and late chronotypes. Several studies showed that students with chronotype short sleep duration obtain lower grades, suggesting starting times handicap their performance. How chronotype, duration, time of day impact is not clear. At Dutch high school, we collected 40,890 grades obtained variety subjects over an entire year. found the strength effect on...
The heat dissipation limit theory suggests that generated during metabolism limits energy intake and, thus, reproductive output. Experiments in laboratory strains of mice and rats, also domestic livestock generally support this theory. Selection for many generations the has increased litter size or productivity these animals. To test wider validity theory, we studied common voles (Microtus arvalis), which have small sizes by comparison with regular addition wild-caught individuals species to...
ABSTRACT Endogenous daily (circadian) rhythms allow organisms to anticipate changes in the environment. Most mammals are specialized be active during night (nocturnal) or day (diurnal). However, typically nocturnal become diurnal when energetically challenged by cold hunger. The circadian thermo-energetics (CTE) hypothesis predicts that activity patterns reduce energy expenditure (DEE) compared with patterns. Here, we tested CTE quantifying energetic consequences of relevant environmental...
Sleep and wakefulness are not simple, homogenous all-or-none states but represent a spectrum of substates, distinguished by behavior, levels arousal, brain activity at the local global levels. Until now, role hypothalamic circuitry in sleep-wake control was studied primarily with respect to its contribution rapid state transitions. In contrast, whether hypothalamus modulates within-state dynamics (state "quality") functional significance thereof remains unexplored. Here, we show that...
The annual cycle of changing day length (photoperiod) is widely used by animals to synchronise their biology environmental seasonality. In mammals, melatonin the key hormonal relay for photoperiodic message, governing thyroid-stimulating hormone (TSH) production in pars tuberalis (PT) pituitary stalk. TSH acts on neighbouring hypothalamic cells known as tanycytes, which turn control function through effects thyroid (TH) signalling, mediated changes expression type II and III deiodinases...
Significance Circadian clocks throughout the body control mammalian physiology. Disruption of circadian rhythms associated with modern 24/7 societies results in adverse metabolic consequences, but underlying mechanisms are unknown. Internal desynchrony between phase central and peripheral is believed to be a major contributor these consequences. Here, first direct test this assumption, we show that ∼6-h misalignment brain tissues insufficient induce obesity glucose intolerance mice. These...
Significance In modern societies, people are regularly exposed to artificial light (e.g., light-emitting electronic devices). Dim in the evening (DLE) imposes an extension of solar day, increasing our alertness before bedtime, delaying melatonin timing and sleep onset, sleepiness next morning. Using laboratory mice as a model organism, we show that 2 wk 4-h, 20-lux DLE postpones rest–activity rhythms, delays molecular rhythms brain body, reverses diurnal pattern short-term memory...
Abstract Body temperature is an important physiological parameter in many studies of laboratory mice. Continuous assessment body has traditionally required surgical implantation a telemeter, but this invasive procedure adversely impacts animal welfare. Near-infrared thermography provides non-invasive alternative by continuously measuring the highest on outside (T skin ), reliability these recordings as proxy for continuous core ) measurements not been assessed. Here, T (30 s resolution) and...
Mice with targeted gene disruption have provided important information about the molecular mechanisms of circadian clock function. A full understanding roles circadian-relevant genes requires manipulation their expression in a tissue-specific manner, ideally including high efficiency within suprachiasmatic nuclei (SCN). To date, conditional SCN has been difficult. In previously developed mouse line, Cre recombinase was inserted into vesicular GABA transporter (Vgat) locus. Since virtually...
Daily torpor is used by small mammals to reduce daily energy expenditure in response energetic challenges. Optimizing the timing of allows maximize its benefits and, accordingly, typically occurs late night and early morning most species. The regulatory mechanisms underlying such temporal regulation have however not been elucidated. Direct control circadian clock indirect through food intake both suggested as possible mechanisms. Here, feeding cycles outside range brain-specific mutations...
Animals studies support the notion that striatal cholinergic interneurons (ChIs) play a central role in basal ganglia function by regulating associative learning, reward processing, and motor control. In nucleus accumbens (NAc), brain region mediates rewarding properties of substance abuse, acetylcholine regulates glutamatergic, dopaminergic, GABAergic neurotransmission naïve mice. However, it is unclear how ChIs orchestrate control these neurotransmitters/modulators to determine synaptic...
Monitoring body temperature and energy expenditure in freely-moving laboratory mice remains a powerful methodology used widely across variety of disciplines-including circadian biology, sleep research, metabolic phenotyping, the study regulation. Some most pronounced changes are observed when small heterothermic species reduce their during daily torpor. Daily torpor is an saving strategy characterized by dramatic reductions employed other challenged to meet energetic demands. Typical...
Abstract Disturbing the circadian regulation of physiology by disruption rhythmic environment is associated with adverse health outcomes but underlying mechanisms are unknown. Here, response central and peripheral clocks to an advance or delay light‐dark cycle was determined in mice. This identified transient damping as a consequence advanced cycle. Similar depression rhythm amplitude observed mice exposed repeated phase shifts. To assess metabolic consequences such isolation, temporally...
Circadian rhythms are driven by daily oscillations of gene expression. An important tool for studying cellular and tissue circadian is the use a reporter, such as bioluminescence from reporter luciferase controlled rhythmically expressed interest. Here we describe methods that allow measurement freely moving mouse housed in standard cage. Using LumiCycle In Vivo (Actimetrics), determined conditions detection PER2 PER2::LUC, behaving mice. The applies background subtraction corrects effects...