Johanna Meijer

Johanna H. Meijer (born 26 March 1959) is a Dutch scientist who has contributed to the fields of chronobiology and neuroscience. She initiated a nationwide program, involving eight Dutch universities to study the effects of clock disturbance on human health and biodiversity. Meijer is the 2016 recipient of the Aschoff and Honma Prize.

Biography Academic career Meijer attended Leiden University in the Netherlands, where she obtained her master's degree (cum laude) in the Department of Biology, Physics, and Medicine. Meijer continued building on Groos' foundational work, allowing for translational research, and expanded electrophysiological techniques to in-vivo recordings. In 1989, she completed her PhD. in Medical Sciences (cum laude).

Major discoveries

Identification of the mechanism for photoperiodic encoding by the central clock Identification of glutamate neurotransmitter for entrainment to the external light-dark cycle and GABA neurotransmitter for entrainment within the central clock Discovery of short wavelength photoreceptor role for photoentrainment Identification of blue, green, and red light response in the central clock of humans by fMRI Identification of clock response to physical activity and sleep

Research and achievements Light serves as the primary environmental cue for the mammalian circadian clock, a topic that has been central to Meijer's work from the outset of her career. Her early studies established that glutamate is the main neurotransmitter conveying photic signals from the eye to the suprachiasmatic nucleus (SCN), This work contributed to a unique national initiative that brought together eight universities, numerous municipalities, and various organizations to mitigate nocturnal light emission and protect public health as well as biodiversity. depression, ADHD, and cancer-related fatigue, while exploring pharmacological strategies to strengthen circadian resilience. Through the lens of complexity science, Meijer continues to unravel the nonlinear, dynamic feedback loops that govern the continuous integration of environmental and endogenous signals within the circadian system.

Awards and recognitions

2026: Knight of the Order of the Netherlands Lion. 2021: Member of Academia Europaea 2020: Dutch National Research Agenda Grant of 10.2 million euros– "BioClock Consortium". www.bioclockconsortium.org 2020: "Ambassador of the Night" Initiative of the Dutch Nature and Environment Federation. 2019: European Advanced Research Grant of 2.2 million euros, ERC: "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) 2015: Board member, National Research Agenda (NWO) Complexity cluster; successfully raised 19.5 million euros on Dutch Complexity Research 2014–Present: Member of the Royal Dutch Society of Sciences. 2013 – 2019: Visiting Professor- Nuffield Laboratory of Ophthalmology, Sleep and Circadian Neuroscience Institute, Dept. of Ophthalmology, University of Oxford, Oxford, UK 1989: Fellowship of the Royal Dutch Academy of Sciences.