Professor
Joke H. Meijer
Research:
My lab focusses on 24-hour rhythms in bodily functions. Rhythms of 24-hours are generated in an evolutionary old part of the brain, called the suprachiasmatic nuclei. Individual cells of this structure produce rhythms of about 24-hours. The clock cells are mutually synchronized and are responsive to external light to adapt to the external light-dark cycle. Disturbances in the clock can give rise to sleep disturbances, obesity and depression. Artificial illumination, shift work, and life style are a challenge for our 24-hour system in modern society.
The topics covered in my group are:
Neuronal network organization of the circadian clock
Cellular analysis of clock cells
Sleep disorders and disease (cancer, aging, metabolic syndrome, depression)
Complexity theory; emergent properties of hierarchical neuronal networks
Curriculum Vitae:
I studied neurosciences at Leiden University, and finished my PhD in 1985 on the Neurophysiology of the mammalian circadian pacemaker. I am currently head of the neurophysiology group of the Leiden University Medical Center, and I conduct biomedical and neuroscientific studies on the central mammalian clock. This clock is located at the base of the brain in the suprachiasmatic nuclei. I am appointed as a fellow of the Royal Academy of Sciences and have obtained a full Professorship in 2007. I am also appointed as a visiting professor at Oxford University and ‘Member at Large’ of the Society for Research on Biological Rhythms. My work is characterized by a multidisciplinary approach, combining electrophysiological recordings with modern imaging techniques. Over the past ten years, I have gained interest in theoretical aspects of the circadian system and complexity, and I’m collaborating with theoretical physicists. I am a member of the Dutch Royal Society of Sciences, and of the board of NWO (Dutch Organization for Scientific Research) that has successfully launched a new program on Complexity.
Publications
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Environmental 24-hr Cycles Are Essential for Health.
Lucassen EA, Coomans CP, van Putten M, de Kreij SR , van Genugten JHLT, Sutorius RPM, de Rooij KE, van der Velde M, Verhoeve SL, Smit JWA, Löwik CWGM, Smits HH, Guigas B, Aartsma-Rus AM, Meijer, JH.
(2016) Current Biol.
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Seasonal induction of GABAergic excitation in the central mammalian clock,
Farajnia S, van Westering TLE, Meijer JH, Michel S.,
PNAS, 111, no 26, 9627-9632. Doi: 10.1073/pnas
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Long-term effects of sleep deprivation on neuronal activity in four hypothalamic areas.
• Fifel K, Meijer JH, Deboer T (2018).
Neurobiol Dis. 109(Pt A):54-63. doi: 10.1016/j.nbd.2017.10.005.
Groups:
Meijer Lab / Circadian Clocks