Mammalian circadian systems: Organization and modern life challenges

Acta Physiologica, Год журнала: 2020, Номер 231(3)

Опубликована: Сен. 1, 2020

Abstract Humans and other mammalian species possess an endogenous circadian clock system that has evolved in adaptation to periodically reoccurring environmental changes drives rhythmic biological functions, as well behavioural outputs with approximately 24‐hour period. In mammals, body clocks are hierarchically organized, encompassing a so‐called pacemaker the hypothalamic suprachiasmatic nucleus (SCN), non‐SCN brain peripheral clocks, cell‐autonomous oscillators within virtually every cell type. A functional machinery on molecular level, alignment among synchronization between exogenous cycles been shown be crucial for our health well‐being. Yet, modern life constantly poses widespread challenges internal example artificial lighting, shift work trans‐meridian travel, potentially leading disruption or misalignment emergence of associated diseases. For instance many us experience mismatch sleep timing free days (social jetlag) everyday lives without being aware consequences may arise from such chronic misalignment, Hence, this review provides overview organization built‐up system, its interactions outside world, pathologies arising misalignment.

Язык: Английский

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A daily temperature rhythm in the human brain predicts survival after brain injury

Brain, Год журнала: 2021, Номер 145(6), С. 2031 - 2048

Опубликована: Дек. 16, 2021

Abstract Patients undergo interventions to achieve a ‘normal’ brain temperature; parameter that remains undefined for humans. The profound sensitivity of neuronal function temperature implies the should be isothermal, but observations from patients and non-human primates suggest significant spatiotemporal variation. We aimed determine clinical relevance in by establishing how much it varies healthy adults. retrospectively screened data all recruited Collaborative European NeuroTrauma Effectiveness Research Traumatic Brain Injury (CENTER-TBI) High Resolution Intensive Care Unit Sub-Study. Only with direct measurements without targeted management were included. To interpret patient analyses, we prospectively 40 adults (20 males, 20 females, 20–40 years) thermometry using magnetic resonance spectroscopy. Participants scanned morning, afternoon, late evening single day. In (n = 114), ranged 32.6 42.3°C mean (38.5 ± 0.8°C) exceeded body (37.5 0.5°C, P < 0.0001). Of 100 eligible rhythm analysis, 25 displayed daily rhythm, range decreased older (P 0.018). participants, 36.1 40.9°C; 0.4°C) oral (36.0 0.5°C) was 0.36°C higher luteal females relative follicular males 0.0006 0.0001, respectively). Temperature increased age, most notably deep regions (0.6°C over years, 0.0002), varied spatially 2.41 0.46°C highest temperatures thalamus. time day, especially (0.86°C, 0.0001), lowest at night. From built HEATWAVE—a 4D map human temperature. Testing HEATWAVE patients, found lack odds death intensive care 21-fold 0.016), whilst absolute maxima or minima did not predict outcome. A warmer associated survival 0.035), however, ageing 10 years 11-fold 0.0002). Human is more than previously assumed—by sex, menstrual cycle, region, This has major implications monitoring management, rhythmicity emerging as one strongest predictors after injury. conclude rhythmic variation—not temperature—is way which physiology may distinguished pathophysiology.

Язык: Английский

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Sleep and thermoregulation

Current Opinion in Physiology, Год журнала: 2019, Номер 15, С. 7 - 13

Опубликована: Ноя. 26, 2019

In homeothermic animals sleep preparatory behaviours often promote thermal efficiency, including warmth-seeking, adopting particular postures (curling up, head tucking) and nest building, all promoting warmer skin microclimates. Skin warmth induces NREM body cooling via circuitry that connects sensation to the preoptic hypothalamus. Coupling induction lower temperature could serve minimise energy expenditure or allow reallocation. Cooling during may also induce transcriptional changes in genes whose products facilitate housekeeping functions measure time spent sleeping.

Язык: Английский

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Development of the circadian system in early life: maternal and environmental factors

Journal of PHYSIOLOGICAL ANTHROPOLOGY, Год журнала: 2022, Номер 41(1)

Опубликована: Май 16, 2022

Abstract In humans, an adaptable internal biological system generates circadian rhythms that maintain synchronicity of behavior and physiology with the changing demands 24-h environment. Development begins in utero continues throughout first few years life. Maturation clock can be measured through sleep/wake patterns hormone secretion. Circadian rhythms, by definition, persist absence environmental input; however, their ability to adjust external time cues is vital for adaptation entrainment The significance these factors influence emergence a stable life remain poorly understood. Infants raised our post-modern world face adverse signals, such as artificial light mistimed hormonal via breast milk, which may increase interference physiological mechanisms promote synchronization. This review describes very early developmental stages common misalignment scenarios make developing more susceptible conflicting temporal disorder between maternal, fetal, infant, peripheral clocks.

Язык: Английский

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Insomnia, sleep loss, and circadian sleep disturbances in mood disorders: a pathway toward neurodegeneration and neuroprogression? A theoretical review

CNS Spectrums, Год журнала: 2021, Номер 27(3), С. 298 - 308

Опубликована: Янв. 11, 2021

Abstract The present paper aims at reviewing and commenting on the relationships between sleep circadian phasing alterations neurodegenerative/neuroprogressive processes in mood disorder. We carried out a systematic review, according to Preferred Reporting Items for Systematic Reviews Meta-Analyses guidelines, PubMed, PsycINFO, Embase electronic databases literature related disorders, disturbances, relation (1) neuroinflammation, (2) activation of stress system, (3) oxidative stress, (4) accumulation neurotoxic proteins, (5) neuroprotection deficit. Seventy articles were collectively selected analyzed. Experimental clinical studies revealed that insomnia, conditions loss, altered may favor neurodegeneration neuroprogression disorders. These disturbances induce state chronic inflammation by enhancing both directly indirectly, via microglia astrocytes activation. They act as neurobiological stressors over-activating system negatively influence neural plasticity causing neuronal damage. In addition, deficit hence contributing neuroprogression. Targeting practice hold neuroprotective value

Язык: Английский

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