1
|
Finger A, Kramer A. Mammalian circadian systems: Organization and modern life challenges. Acta Physiol (Oxf) 2021; 231:e13548. [PMID: 32846050 DOI: 10.1111/apha.13548] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 08/04/2020] [Accepted: 08/11/2020] [Indexed: 12/11/2022]
Abstract
Humans and other mammalian species possess an endogenous circadian clock system that has evolved in adaptation to periodically reoccurring environmental changes and drives rhythmic biological functions, as well as behavioural outputs with an approximately 24-hour period. In mammals, body clocks are hierarchically organized, encompassing a so-called pacemaker clock in the hypothalamic suprachiasmatic nucleus (SCN), non-SCN brain and peripheral clocks, as well as cell-autonomous oscillators within virtually every cell type. A functional clock machinery on the molecular level, alignment among body clocks, as well as synchronization between endogenous circadian and exogenous environmental cycles has been shown to be crucial for our health and well-being. Yet, modern life constantly poses widespread challenges to our internal clocks, for example artificial lighting, shift work and trans-meridian travel, potentially leading to circadian disruption or misalignment and the emergence of associated diseases. For instance many of us experience a mismatch between sleep timing on work and free days (social jetlag) in our everyday lives without being aware of health consequences that may arise from such chronic circadian misalignment, Hence, this review provides an overview of the organization and molecular built-up of the mammalian circadian system, its interactions with the outside world, as well as pathologies arising from circadian disruption and misalignment.
Collapse
Affiliation(s)
- Anna‐Marie Finger
- Laboratory of Chronobiology Institute for Medical immunology Charité Universitätsmedizin Berlin Berlin Germany
- Berlin Institute of Health (BIH) Berlin Germany
| | - Achim Kramer
- Laboratory of Chronobiology Institute for Medical immunology Charité Universitätsmedizin Berlin Berlin Germany
- Berlin Institute of Health (BIH) Berlin Germany
| |
Collapse
|
2
|
Khedkar PH. Intermittent fasting-The new lifestyle? Acta Physiol (Oxf) 2020; 229:e13518. [PMID: 32485083 DOI: 10.1111/apha.13518] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Revised: 05/27/2020] [Accepted: 05/27/2020] [Indexed: 12/28/2022]
Affiliation(s)
- Pratik H. Khedkar
- Charité—Universitätsmedizin Berlin, corporate member of the Freie Universität BerlinHumboldt Universität zu Berlin and the Berlin Institute of HealthInstitute of Vegetative Physiology Berlin Germany
| |
Collapse
|
3
|
Fafrowicz M, Bohaterewicz B, Ceglarek A, Cichocka M, Lewandowska K, Sikora-Wachowicz B, Oginska H, Beres A, Olszewska J, Marek T. Beyond the Low Frequency Fluctuations: Morning and Evening Differences in Human Brain. Front Hum Neurosci 2019; 13:288. [PMID: 31507393 PMCID: PMC6718916 DOI: 10.3389/fnhum.2019.00288] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Accepted: 08/05/2019] [Indexed: 01/12/2023] Open
Abstract
Human performance, alertness, and most biological functions express rhythmic fluctuations across a 24-h-period. This phenomenon is believed to originate from differences in both circadian and homeostatic sleep-wake regulatory processes. Interactions between these processes result in time-of-day modulations of behavioral performance as well as brain activity patterns. Although the basic mechanism of the 24-h clock is conserved across evolution, there are interindividual differences in the timing of sleep-wake cycles, subjective alertness and functioning throughout the day. The study of circadian typology differences has increased during the last few years, especially research on extreme chronotypes, which provide a unique way to investigate the effects of sleep-wake regulation on cerebral mechanisms. Using functional magnetic resonance imaging (fMRI), we assessed the influence of chronotype and time-of-day on resting-state functional connectivity. Twenty-nine extreme morning- and 34 evening-type participants underwent two fMRI sessions: about 1 h after wake-up time (morning) and about 10 h after wake-up time (evening), scheduled according to their declared habitual sleep-wake pattern on a regular working day. Analysis of obtained neuroimaging data disclosed only an effect of time of day on resting-state functional connectivity; there were different patterns of functional connectivity between morning (MS) and evening (ES) sessions. The results of our study showed no differences between extreme morning-type and evening-type individuals. We demonstrate that circadian and homeostatic influences on the resting-state functional connectivity have a universal character, unaffected by circadian typology.
Collapse
Affiliation(s)
- Magdalena Fafrowicz
- Neuroimaging Group, Malopolska Centre of Biotechnology, Jagiellonian University, Krakow, Poland.,Department of Cognitive Neuroscience and Neuroergonomics, Institute of Applied Psychology, Jagiellonian University, Krakow, Poland
| | - Bartosz Bohaterewicz
- Department of Cognitive Neuroscience and Neuroergonomics, Institute of Applied Psychology, Jagiellonian University, Krakow, Poland
| | - Anna Ceglarek
- Department of Cognitive Neuroscience and Neuroergonomics, Institute of Applied Psychology, Jagiellonian University, Krakow, Poland
| | - Monika Cichocka
- Chair of Radiology, Medical College, Jagiellonian University, Krakow, Poland
| | - Koryna Lewandowska
- Department of Cognitive Neuroscience and Neuroergonomics, Institute of Applied Psychology, Jagiellonian University, Krakow, Poland
| | - Barbara Sikora-Wachowicz
- Department of Cognitive Neuroscience and Neuroergonomics, Institute of Applied Psychology, Jagiellonian University, Krakow, Poland
| | - Halszka Oginska
- Department of Cognitive Neuroscience and Neuroergonomics, Institute of Applied Psychology, Jagiellonian University, Krakow, Poland
| | - Anna Beres
- Department of Cognitive Neuroscience and Neuroergonomics, Institute of Applied Psychology, Jagiellonian University, Krakow, Poland
| | - Justyna Olszewska
- Department of Psychology, University of Wisconsin-Oshkosh, Oshkosh, WI, United States
| | - Tadeusz Marek
- Department of Cognitive Neuroscience and Neuroergonomics, Institute of Applied Psychology, Jagiellonian University, Krakow, Poland
| |
Collapse
|
4
|
Persson PB, Bondke Persson A. Circadian rhythms. Acta Physiol (Oxf) 2019; 225:e13220. [PMID: 30457219 DOI: 10.1111/apha.13220] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Accepted: 11/15/2018] [Indexed: 12/25/2022]
Affiliation(s)
- Pontus B. Persson
- Institute of Vegetative Physiology; Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health; Berlin Germany
| | - Anja Bondke Persson
- Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health; Berlin Germany
| |
Collapse
|