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
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.
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.
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
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.