Circadian rhythmicity is a fundamental feature of biological organization and is deeply rooted in the biology of all living organisms. These rhythms have developed as an adaptation to the recurring changes in the environment brought about by the rotation of the Earth around its axis and the orbit of the Earth around the Sun. In order to anticipate these changes, innate clocks have evolved that allow organisms to prepare for the predictable onset of night and day. Our circadian system evolved as a robust mechanism to increase fitness. However, in modern society, the widespread use of artificial light and electronic devices has drastically—and rather suddenly—changed the photic environment in which we live, and compelling studies now demonstrate that a lack of a proper light-dark cycle is detrimental to human health. Recent data from our group at the Circadian Clock lab and others showed that deviating from the natural cycles of light and dark can have severe effects on clock function. Reduced function of the central clock causes key organ systems to lose their synchrony and/or 24-hour pattern, increasing the risk of developing a wide range of severe health conditions, including diabetes, neurological and cardiovascular disease, immune dysfunction, cancer, sleep disorders, and depression. With our modern society’s 24-hour economy and our increasing use of artificial light, perturbations in our clock function are likely to continue to increase, underscoring the importance of developing strategies to strengthen clock function.
Topics of the Meijer group:
- Neuronal network organization of the circadian clock in day active vs night active animals
- Light responses of the circadian system (retinal photopigments, jet lag, shift work)
- Clinical: aging, sleep, metabolic syndrome, depression, cancer
- Sleep and exercise: non-photic effects on the SCN clock
- Complexity theory; emergent properties of hierarchical neuronal networks
- Chronopharmacology: strategies for enhancing clock function, optimizing drug timing
- Field research, ecology, biodiversity, population dynamics, nocturnal light pollution
Find more information at the Circadian clock lab of the Leiden University Medical Center.
2020: Ten million euro research grant for the BioClock consortium by the Dutch National Research Agenda
“With our BioClock consortium we are going to make sure that the biological clock is, and remains, healthy. Our plans cover the society as a whole: from human health and disease to the natural environment and protection of biodiversity. Topics such as health effects of shift work, optimal times for immunotherapy for cancer and flu vaccinations are all covered,” explains project leader and Professor of Neurophysiology, Joke Meijer.
“This project is unparalleled internationally in the scope and applicability of biological clock research. After years of fundamental research, we can finally start working on concrete applications for society”.
With the biological clock in the center, the partners in the consortium will jointly develop strategies that contribute to a sustainable future for our planet and its inhabitants. The consortium receives almost 10 million euros and has academic and non-academic partners, from the National Institute for Public Health and the Environment (RIVM) to municipalities and from environmental organizations to health and safety services. Find more information on BioClock Consortium
“Miljoenensubsidie om biologische klok gezond te houden”– Universiteit Leiden
- Caputo R., Poirel VJ., Paive I., Boutillier AL., Challet E., Meijer JH., Raison S. 2023 Circadian functioning of Locus Cœruleus of the nocturnal rat and diurnal rodent Arvicanthis. Neuroscience Letters 2023 (pre-proofs)
- Gaston, K.J. and Meijer, J.H. 2023. Light effects across species in nature: A focus on solutions. Biological Implications of Circadian Disruption: A Health Challenge in the Modern World. (LK Fonken & RJ Nelson, eds). Cambridge University Press: Cambridge UK. (In press).
- Meijer JH, de Rover M, de Torres Gutiérreza P, Swaab DF, van Osch MJP, and Schoonderwoerd RA. (2022) Reply to Sharifpour et al.: Light response measurement of the human SCN by 7T fMRI PNAS 2022 Vol. 119 No. 49 e2215410119 doi: 10.1073/pnas.2215410119
- Schoonderwoerd RA, de Torres Gutiérrez P, Blommers R, van Beurden AW, Coenen TCJJ, Klett NJ, Michel SH, Meijer JH. (2022) Inhibitory responses to retinohypothalamic tract stimulation in the circadian clock of the diurnal rodent Rhabdomys pumilio. The FASEB Journal. 2022;00 :e22415. doi: 10.1096/fj.202200477R
- Wang Y, van der Zanden SY, van Leerdam S, Tersteeg MMH, Kastelein A., Michel S., Neefjes J., Meijer JH, Deboer T. (2022) Induction of Fatigue by Specific Anthracycline Cancer Drugs through Disruption of the Circadian Pacemaker. Cancers (Basel). May 13;14(10):2421. doi: 10.3390/cancers14102421
- Schoonderwoerd RA, de Rover M, Janse JAM, Hirschler L, Willemse CR, Scholten L, Klop I, van Berloo S, van Osch MJP, Swaab DF, Meijer JH (2022). The photobiology of the human circadian clock. PNAS, Mar 29;119(13):e2118803119. doi: 10.1073/pnas.2118803119
- January 27: Lecture in workshop From the pineal to biological rhythms through melatonin: a conference in honour of Prof. Paul Pevet. ‘Behavioural feedback on the central clock in diurnal mammals’
- February 2: Mini-lecture at StrandLAB Almere – outdoor science on ‘The rhythm of darkness’ (in Dutch)
For students with a possible career in science
- Interview with Joke Meijer: How do you know you want to become a scientist?
- April 2020: Meijer & Oude Vrielink (2020): Using surgical wrapping material for the fabrication of respirator masks. PLOS ONE.
As a community outreach project, this paper has been shortened and made available in over 17 languages.
It is freely obtainable through a dedicated website: https://coronamedicalmasks.org/ 110.000+ visits from 150+ different countries.
Recent prizes, awards, and grants
- 2020: 9.7 Million euro research grant Dutch National Research Agenda BioClock consortium Link1 Link2
- 2019: 2.4 Million euro research grant ERC Advanced Grant: “The circadian clock in day-active species: preserving our health in modern society”
- 2016: Aschoff and Honma Prize in Biological Rhythm Research (International Selection Committee, chaired by Dr. Takao Kondo)
Current special positions of Joke Meijer
- 2020: “Ambassador of the Night” (Natuur en Milieufederatie Nederland).
- Visiting Professor Oxford University
- Member of Academia Europeae – section Physiology & Neuroscience
- Member of the Royal Holland Society of Sciences and Humanities
- Member of the Life Sciences Board, Lorentz Center, Leiden
- National board of Complexity research (Grip on Complexity)
Societal Impact (For more, see media)
- July 2021 Artikel Trouw “Nederlandse onderzoekers proberen biologische klok beter in de pas te laten lopen”
- January 2020: Diligentia lezing “De Biologische Klok in de Moderne Samenleving”, Den Haag.
- November 2019: Cleveringa lezing, Parijs.
- Oktober 2019: Lezing tijdens de Nacht van de Nacht in Artis. Titel: Waarom is het donker zo belangrijk voor de mens? More information (in Dutch).
- 2016: Priceless: The Value Proposition for the Humanities – Annual Winter Lecture at the Royal Holland Society of Sciences and Humanities (KHMW) by prof. G.D. Block, Chancellor and Distinguished Professor of Psychiatry and Biobehavioral Science at UCLA, USA (Main organizer: prof. J.H. Meijer)