A new scientific study has revealed key mechanisms underlying the functioning of the circadian clock. The research, led by Ikerbasque researcher Dr Mariana Astiz from the Laboratory of Circadian Physiology at the Achucarro Basque Center for Neuroscience, a BERC–Basque Excellence Research Centre, shows that the central circadian pacemaker in adults is capable of responding to glucocorticoids.
Until now, the scientific community had assumed that, in adults, the circadian pacemaker located in the suprachiasmatic nucleus (SCN) of the hypothalamus became insensitive to glucocorticoids, a type of hormone involved in regulating sleep–wake cycles and stress responses.
However, the research team discovered that astrocytes in the SCN are the brain cells capable of detecting and responding to glucocorticoids through a specific receptor. These mechanisms enable the brain to adjust circadian rhythms to the environment.
The study, published in the prestigious scientific journal PLOS Biology, therefore challenges a concept that had been established in the field of circadian biology for more than 20 years.
According to Dr Astiz, “These findings suggest that glucocorticoids provide information to the brain’s central clock through astrocytes. These mechanisms are crucial for keeping the entire body synchronised with the environment. Understanding them opens up new possibilities for mitigating the negative health effects of sleep disorders, chronic stress and jet lag.”
This scientific milestone is the result of years of work and an international collaborative effort between Dr Astiz’s laboratory and that of Prof. Dr med. Malte Spielmann in Germany.
Link to the study: https://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.3003870
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